fs/btrfs/ioctl.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2007 Oracle.  All rights reserved.
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/bio.h>
   8 #include <linux/file.h>
   9 #include <linux/fs.h>
  10 #include <linux/fsnotify.h>
  11 #include <linux/pagemap.h>
  12 #include <linux/highmem.h>
  13 #include <linux/time.h>
  14 #include <linux/string.h>
  15 #include <linux/backing-dev.h>
  16 #include <linux/mount.h>
  17 #include <linux/namei.h>
  18 #include <linux/writeback.h>
  19 #include <linux/compat.h>
  20 #include <linux/security.h>
  21 #include <linux/xattr.h>
  22 #include <linux/mm.h>
  23 #include <linux/slab.h>
  24 #include <linux/blkdev.h>
  25 #include <linux/uuid.h>
  26 #include <linux/btrfs.h>
  27 #include <linux/uaccess.h>
  28 #include <linux/iversion.h>
  29 #include "ctree.h"
  30 #include "disk-io.h"
  31 #include "transaction.h"
  32 #include "btrfs_inode.h"
  33 #include "print-tree.h"
  34 #include "volumes.h"
  35 #include "locking.h"
  36 #include "inode-map.h"
  37 #include "backref.h"
  38 #include "rcu-string.h"
  39 #include "send.h"
  40 #include "dev-replace.h"
  41 #include "props.h"
  42 #include "sysfs.h"
  43 #include "qgroup.h"
  44 #include "tree-log.h"
  45 #include "compression.h"
  46
  47 #ifdef CONFIG_64BIT
  48 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
  49  * structures are incorrect, as the timespec structure from userspace
  50  * is 4 bytes too small. We define these alternatives here to teach
  51  * the kernel about the 32-bit struct packing.
  52  */
  53 struct btrfs_ioctl_timespec_32 {
  54         __u64 sec;
  55         __u32 nsec;
  56 } __attribute__ ((__packed__));
  57
  58 struct btrfs_ioctl_received_subvol_args_32 {
  59         char    uuid[BTRFS_UUID_SIZE];  /* in */
  60         __u64   stransid;               /* in */
  61         __u64   rtransid;               /* out */
  62         struct btrfs_ioctl_timespec_32 stime; /* in */
  63         struct btrfs_ioctl_timespec_32 rtime; /* out */
  64         __u64   flags;                  /* in */
  65         __u64   reserved[16];           /* in */
  66 } __attribute__ ((__packed__));
  67
  68 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
  69                                 struct btrfs_ioctl_received_subvol_args_32)
  70 #endif
  71
  72 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
  73 struct btrfs_ioctl_send_args_32 {
  74         __s64 send_fd;                  /* in */
  75         __u64 clone_sources_count;      /* in */
  76         compat_uptr_t clone_sources;    /* in */
  77         __u64 parent_root;              /* in */
  78         __u64 flags;                    /* in */
  79         __u64 reserved[4];              /* in */
  80 } __attribute__ ((__packed__));
  81
  82 #define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
  83                                struct btrfs_ioctl_send_args_32)
  84 #endif
  85
  86 static int btrfs_clone(struct inode *src, struct inode *inode,
  87                        u64 off, u64 olen, u64 olen_aligned, u64 destoff,
  88                        int no_time_update);
  89
  90 /* Mask out flags that are inappropriate for the given type of inode. */
  91 static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
  92                 unsigned int flags)
  93 {
  94         if (S_ISDIR(inode->i_mode))
  95                 return flags;
  96         else if (S_ISREG(inode->i_mode))
  97                 return flags & ~FS_DIRSYNC_FL;
  98         else
  99                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 100 }
 101
 102 /*
 103  * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS
 104  * ioctl.
 105  */
 106 static unsigned int btrfs_inode_flags_to_fsflags(unsigned int flags)
 107 {
 108         unsigned int iflags = 0;
 109
 110         if (flags & BTRFS_INODE_SYNC)
 111                 iflags |= FS_SYNC_FL;
 112         if (flags & BTRFS_INODE_IMMUTABLE)
 113                 iflags |= FS_IMMUTABLE_FL;
 114         if (flags & BTRFS_INODE_APPEND)
 115                 iflags |= FS_APPEND_FL;
 116         if (flags & BTRFS_INODE_NODUMP)
 117                 iflags |= FS_NODUMP_FL;
 118         if (flags & BTRFS_INODE_NOATIME)
 119                 iflags |= FS_NOATIME_FL;
 120         if (flags & BTRFS_INODE_DIRSYNC)
 121                 iflags |= FS_DIRSYNC_FL;
 122         if (flags & BTRFS_INODE_NODATACOW)
 123                 iflags |= FS_NOCOW_FL;
 124
 125         if (flags & BTRFS_INODE_NOCOMPRESS)
 126                 iflags |= FS_NOCOMP_FL;
 127         else if (flags & BTRFS_INODE_COMPRESS)
 128                 iflags |= FS_COMPR_FL;
 129
 130         return iflags;
 131 }
 132
 133 /*
 134  * Update inode->i_flags based on the btrfs internal flags.
 135  */
 136 void btrfs_sync_inode_flags_to_i_flags(struct inode *inode)
 137 {
 138         struct btrfs_inode *binode = BTRFS_I(inode);
 139         unsigned int new_fl = 0;
 140
 141         if (binode->flags & BTRFS_INODE_SYNC)
 142                 new_fl |= S_SYNC;
 143         if (binode->flags & BTRFS_INODE_IMMUTABLE)
 144                 new_fl |= S_IMMUTABLE;
 145         if (binode->flags & BTRFS_INODE_APPEND)
 146                 new_fl |= S_APPEND;
 147         if (binode->flags & BTRFS_INODE_NOATIME)
 148                 new_fl |= S_NOATIME;
 149         if (binode->flags & BTRFS_INODE_DIRSYNC)
 150                 new_fl |= S_DIRSYNC;
 151
 152         set_mask_bits(&inode->i_flags,
 153                       S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
 154                       new_fl);
 155 }
 156
 157 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 158 {
 159         struct btrfs_inode *binode = BTRFS_I(file_inode(file));
 160         unsigned int flags = btrfs_inode_flags_to_fsflags(binode->flags);
 161
 162         if (copy_to_user(arg, &flags, sizeof(flags)))
 163                 return -EFAULT;
 164         return 0;
 165 }
 166
 167 /* Check if @flags are a supported and valid set of FS_*_FL flags */
 168 static int check_fsflags(unsigned int flags)
 169 {
 170         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 171                       FS_NOATIME_FL | FS_NODUMP_FL | \
 172                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 173                       FS_NOCOMP_FL | FS_COMPR_FL |
 174                       FS_NOCOW_FL))
 175                 return -EOPNOTSUPP;
 176
 177         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 178                 return -EINVAL;
 179
 180         return 0;
 181 }
 182
 183 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 184 {
 185         struct inode *inode = file_inode(file);
 186         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 187         struct btrfs_inode *binode = BTRFS_I(inode);
 188         struct btrfs_root *root = binode->root;
 189         struct btrfs_trans_handle *trans;
 190         unsigned int fsflags, old_fsflags;
 191         int ret;
 192         u64 old_flags;
 193         unsigned int old_i_flags;
 194         umode_t mode;
 195
 196         if (!inode_owner_or_capable(inode))
 197                 return -EPERM;
 198
 199         if (btrfs_root_readonly(root))
 200                 return -EROFS;
 201
 202         if (copy_from_user(&fsflags, arg, sizeof(fsflags)))
 203                 return -EFAULT;
 204
 205         ret = check_fsflags(fsflags);
 206         if (ret)
 207                 return ret;
 208
 209         ret = mnt_want_write_file(file);
 210         if (ret)
 211                 return ret;
 212
 213         inode_lock(inode);
 214
 215         old_flags = binode->flags;
 216         old_i_flags = inode->i_flags;
 217         mode = inode->i_mode;
 218
 219         fsflags = btrfs_mask_fsflags_for_type(inode, fsflags);
 220         old_fsflags = btrfs_inode_flags_to_fsflags(binode->flags);
 221         if ((fsflags ^ old_fsflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 222                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 223                         ret = -EPERM;
 224                         goto out_unlock;
 225                 }
 226         }
 227
 228         if (fsflags & FS_SYNC_FL)
 229                 binode->flags |= BTRFS_INODE_SYNC;
 230         else
 231                 binode->flags &= ~BTRFS_INODE_SYNC;
 232         if (fsflags & FS_IMMUTABLE_FL)
 233                 binode->flags |= BTRFS_INODE_IMMUTABLE;
 234         else
 235                 binode->flags &= ~BTRFS_INODE_IMMUTABLE;
 236         if (fsflags & FS_APPEND_FL)
 237                 binode->flags |= BTRFS_INODE_APPEND;
 238         else
 239                 binode->flags &= ~BTRFS_INODE_APPEND;
 240         if (fsflags & FS_NODUMP_FL)
 241                 binode->flags |= BTRFS_INODE_NODUMP;
 242         else
 243                 binode->flags &= ~BTRFS_INODE_NODUMP;
 244         if (fsflags & FS_NOATIME_FL)
 245                 binode->flags |= BTRFS_INODE_NOATIME;
 246         else
 247                 binode->flags &= ~BTRFS_INODE_NOATIME;
 248         if (fsflags & FS_DIRSYNC_FL)
 249                 binode->flags |= BTRFS_INODE_DIRSYNC;
 250         else
 251                 binode->flags &= ~BTRFS_INODE_DIRSYNC;
 252         if (fsflags & FS_NOCOW_FL) {
 253                 if (S_ISREG(mode)) {
 254                         /*
 255                          * It's safe to turn csums off here, no extents exist.
 256                          * Otherwise we want the flag to reflect the real COW
 257                          * status of the file and will not set it.
 258                          */
 259                         if (inode->i_size == 0)
 260                                 binode->flags |= BTRFS_INODE_NODATACOW
 261                                               | BTRFS_INODE_NODATASUM;
 262                 } else {
 263                         binode->flags |= BTRFS_INODE_NODATACOW;
 264                 }
 265         } else {
 266                 /*
 267                  * Revert back under same assumptions as above
 268                  */
 269                 if (S_ISREG(mode)) {
 270                         if (inode->i_size == 0)
 271                                 binode->flags &= ~(BTRFS_INODE_NODATACOW
 272                                              | BTRFS_INODE_NODATASUM);
 273                 } else {
 274                         binode->flags &= ~BTRFS_INODE_NODATACOW;
 275                 }
 276         }
 277
 278         /*
 279          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 280          * flag may be changed automatically if compression code won't make
 281          * things smaller.
 282          */
 283         if (fsflags & FS_NOCOMP_FL) {
 284                 binode->flags &= ~BTRFS_INODE_COMPRESS;
 285                 binode->flags |= BTRFS_INODE_NOCOMPRESS;
 286
 287                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 288                 if (ret && ret != -ENODATA)
 289                         goto out_drop;
 290         } else if (fsflags & FS_COMPR_FL) {
 291                 const char *comp;
 292
 293                 binode->flags |= BTRFS_INODE_COMPRESS;
 294                 binode->flags &= ~BTRFS_INODE_NOCOMPRESS;
 295
 296                 comp = btrfs_compress_type2str(fs_info->compress_type);
 297                 if (!comp || comp[0] == 0)
 298                         comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
 299
 300                 ret = btrfs_set_prop(inode, "btrfs.compression",
 301                                      comp, strlen(comp), 0);
 302                 if (ret)
 303                         goto out_drop;
 304
 305         } else {
 306                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 307                 if (ret && ret != -ENODATA)
 308                         goto out_drop;
 309                 binode->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 310         }
 311
 312         trans = btrfs_start_transaction(root, 1);
 313         if (IS_ERR(trans)) {
 314                 ret = PTR_ERR(trans);
 315                 goto out_drop;
 316         }
 317
 318         btrfs_sync_inode_flags_to_i_flags(inode);
 319         inode_inc_iversion(inode);
 320         inode->i_ctime = current_time(inode);
 321         ret = btrfs_update_inode(trans, root, inode);
 322
 323         btrfs_end_transaction(trans);
 324  out_drop:
 325         if (ret) {
 326                 binode->flags = old_flags;
 327                 inode->i_flags = old_i_flags;
 328         }
 329
 330  out_unlock:
 331         inode_unlock(inode);
 332         mnt_drop_write_file(file);
 333         return ret;
 334 }
 335
 336 /*
 337  * Translate btrfs internal inode flags to xflags as expected by the
 338  * FS_IOC_FSGETXATT ioctl. Filter only the supported ones, unknown flags are
 339  * silently dropped.
 340  */
 341 static unsigned int btrfs_inode_flags_to_xflags(unsigned int flags)
 342 {
 343         unsigned int xflags = 0;
 344
 345         if (flags & BTRFS_INODE_APPEND)
 346                 xflags |= FS_XFLAG_APPEND;
 347         if (flags & BTRFS_INODE_IMMUTABLE)
 348                 xflags |= FS_XFLAG_IMMUTABLE;
 349         if (flags & BTRFS_INODE_NOATIME)
 350                 xflags |= FS_XFLAG_NOATIME;
 351         if (flags & BTRFS_INODE_NODUMP)
 352                 xflags |= FS_XFLAG_NODUMP;
 353         if (flags & BTRFS_INODE_SYNC)
 354                 xflags |= FS_XFLAG_SYNC;
 355
 356         return xflags;
 357 }
 358
 359 /* Check if @flags are a supported and valid set of FS_XFLAGS_* flags */
 360 static int check_xflags(unsigned int flags)
 361 {
 362         if (flags & ~(FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE | FS_XFLAG_NOATIME |
 363                       FS_XFLAG_NODUMP | FS_XFLAG_SYNC))
 364                 return -EOPNOTSUPP;
 365         return 0;
 366 }
 367
 368 /*
 369  * Set the xflags from the internal inode flags. The remaining items of fsxattr
 370  * are zeroed.
 371  */
 372 static int btrfs_ioctl_fsgetxattr(struct file *file, void __user *arg)
 373 {
 374         struct btrfs_inode *binode = BTRFS_I(file_inode(file));
 375         struct fsxattr fa;
 376
 377         memset(&fa, 0, sizeof(fa));
 378         fa.fsx_xflags = btrfs_inode_flags_to_xflags(binode->flags);
 379
 380         if (copy_to_user(arg, &fa, sizeof(fa)))
 381                 return -EFAULT;
 382
 383         return 0;
 384 }
 385
 386 static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg)
 387 {
 388         struct inode *inode = file_inode(file);
 389         struct btrfs_inode *binode = BTRFS_I(inode);
 390         struct btrfs_root *root = binode->root;
 391         struct btrfs_trans_handle *trans;
 392         struct fsxattr fa;
 393         unsigned old_flags;
 394         unsigned old_i_flags;
 395         int ret = 0;
 396
 397         if (!inode_owner_or_capable(inode))
 398                 return -EPERM;
 399
 400         if (btrfs_root_readonly(root))
 401                 return -EROFS;
 402
 403         memset(&fa, 0, sizeof(fa));
 404         if (copy_from_user(&fa, arg, sizeof(fa)))
 405                 return -EFAULT;
 406
 407         ret = check_xflags(fa.fsx_xflags);
 408         if (ret)
 409                 return ret;
 410
 411         if (fa.fsx_extsize != 0 || fa.fsx_projid != 0 || fa.fsx_cowextsize != 0)
 412                 return -EOPNOTSUPP;
 413
 414         ret = mnt_want_write_file(file);
 415         if (ret)
 416                 return ret;
 417
 418         inode_lock(inode);
 419
 420         old_flags = binode->flags;
 421         old_i_flags = inode->i_flags;
 422
 423         /* We need the capabilities to change append-only or immutable inode */
 424         if (((old_flags & (BTRFS_INODE_APPEND | BTRFS_INODE_IMMUTABLE)) ||
 425              (fa.fsx_xflags & (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE))) &&
 426             !capable(CAP_LINUX_IMMUTABLE)) {
 427                 ret = -EPERM;
 428                 goto out_unlock;
 429         }
 430
 431         if (fa.fsx_xflags & FS_XFLAG_SYNC)
 432                 binode->flags |= BTRFS_INODE_SYNC;
 433         else
 434                 binode->flags &= ~BTRFS_INODE_SYNC;
 435         if (fa.fsx_xflags & FS_XFLAG_IMMUTABLE)
 436                 binode->flags |= BTRFS_INODE_IMMUTABLE;
 437         else
 438                 binode->flags &= ~BTRFS_INODE_IMMUTABLE;
 439         if (fa.fsx_xflags & FS_XFLAG_APPEND)
 440                 binode->flags |= BTRFS_INODE_APPEND;
 441         else
 442                 binode->flags &= ~BTRFS_INODE_APPEND;
 443         if (fa.fsx_xflags & FS_XFLAG_NODUMP)
 444                 binode->flags |= BTRFS_INODE_NODUMP;
 445         else
 446                 binode->flags &= ~BTRFS_INODE_NODUMP;
 447         if (fa.fsx_xflags & FS_XFLAG_NOATIME)
 448                 binode->flags |= BTRFS_INODE_NOATIME;
 449         else
 450                 binode->flags &= ~BTRFS_INODE_NOATIME;
 451
 452         /* 1 item for the inode */
 453         trans = btrfs_start_transaction(root, 1);
 454         if (IS_ERR(trans)) {
 455                 ret = PTR_ERR(trans);
 456                 goto out_unlock;
 457         }
 458
 459         btrfs_sync_inode_flags_to_i_flags(inode);
 460         inode_inc_iversion(inode);
 461         inode->i_ctime = current_time(inode);
 462         ret = btrfs_update_inode(trans, root, inode);
 463
 464         btrfs_end_transaction(trans);
 465
 466 out_unlock:
 467         if (ret) {
 468                 binode->flags = old_flags;
 469                 inode->i_flags = old_i_flags;
 470         }
 471
 472         inode_unlock(inode);
 473         mnt_drop_write_file(file);
 474
 475         return ret;
 476 }
 477
 478 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 479 {
 480         struct inode *inode = file_inode(file);
 481
 482         return put_user(inode->i_generation, arg);
 483 }
 484
 485 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 486 {
 487         struct inode *inode = file_inode(file);
 488         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 489         struct btrfs_device *device;
 490         struct request_queue *q;
 491         struct fstrim_range range;
 492         u64 minlen = ULLONG_MAX;
 493         u64 num_devices = 0;
 494         u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 495         int ret;
 496
 497         if (!capable(CAP_SYS_ADMIN))
 498                 return -EPERM;
 499
 500         rcu_read_lock();
 501         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 502                                 dev_list) {
 503                 if (!device->bdev)
 504                         continue;
 505                 q = bdev_get_queue(device->bdev);
 506                 if (blk_queue_discard(q)) {
 507                         num_devices++;
 508                         minlen = min_t(u64, q->limits.discard_granularity,
 509                                      minlen);
 510                 }
 511         }
 512         rcu_read_unlock();
 513
 514         if (!num_devices)
 515                 return -EOPNOTSUPP;
 516         if (copy_from_user(&range, arg, sizeof(range)))
 517                 return -EFAULT;
 518         if (range.start > total_bytes ||
 519             range.len < fs_info->sb->s_blocksize)
 520                 return -EINVAL;
 521
 522         range.len = min(range.len, total_bytes - range.start);
 523         range.minlen = max(range.minlen, minlen);
 524         ret = btrfs_trim_fs(fs_info, &range);
 525         if (ret < 0)
 526                 return ret;
 527
 528         if (copy_to_user(arg, &range, sizeof(range)))
 529                 return -EFAULT;
 530
 531         return 0;
 532 }
 533
 534 int btrfs_is_empty_uuid(u8 *uuid)
 535 {
 536         int i;
 537
 538         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 539                 if (uuid[i])
 540                         return 0;
 541         }
 542         return 1;
 543 }
 544
 545 static noinline int create_subvol(struct inode *dir,
 546                                   struct dentry *dentry,
 547                                   const char *name, int namelen,
 548                                   u64 *async_transid,
 549                                   struct btrfs_qgroup_inherit *inherit)
 550 {
 551         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 552         struct btrfs_trans_handle *trans;
 553         struct btrfs_key key;
 554         struct btrfs_root_item *root_item;
 555         struct btrfs_inode_item *inode_item;
 556         struct extent_buffer *leaf;
 557         struct btrfs_root *root = BTRFS_I(dir)->root;
 558         struct btrfs_root *new_root;
 559         struct btrfs_block_rsv block_rsv;
 560         struct timespec64 cur_time = current_time(dir);
 561         struct inode *inode;
 562         int ret;
 563         int err;
 564         u64 objectid;
 565         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 566         u64 index = 0;
 567         uuid_le new_uuid;
 568
 569         root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 570         if (!root_item)
 571                 return -ENOMEM;
 572
 573         ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
 574         if (ret)
 575                 goto fail_free;
 576
 577         /*
 578          * Don't create subvolume whose level is not zero. Or qgroup will be
 579          * screwed up since it assumes subvolume qgroup's level to be 0.
 580          */
 581         if (btrfs_qgroup_level(objectid)) {
 582                 ret = -ENOSPC;
 583                 goto fail_free;
 584         }
 585
 586         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 587         /*
 588          * The same as the snapshot creation, please see the comment
 589          * of create_snapshot().
 590          */
 591         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 8, false);
 592         if (ret)
 593                 goto fail_free;
 594
 595         trans = btrfs_start_transaction(root, 0);
 596         if (IS_ERR(trans)) {
 597                 ret = PTR_ERR(trans);
 598                 btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 599                 goto fail_free;
 600         }
 601         trans->block_rsv = &block_rsv;
 602         trans->bytes_reserved = block_rsv.size;
 603
 604         ret = btrfs_qgroup_inherit(trans, 0, objectid, inherit);
 605         if (ret)
 606                 goto fail;
 607
 608         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
 609         if (IS_ERR(leaf)) {
 610                 ret = PTR_ERR(leaf);
 611                 goto fail;
 612         }
 613
 614         btrfs_mark_buffer_dirty(leaf);
 615
 616         inode_item = &root_item->inode;
 617         btrfs_set_stack_inode_generation(inode_item, 1);
 618         btrfs_set_stack_inode_size(inode_item, 3);
 619         btrfs_set_stack_inode_nlink(inode_item, 1);
 620         btrfs_set_stack_inode_nbytes(inode_item,
 621                                      fs_info->nodesize);
 622         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 623
 624         btrfs_set_root_flags(root_item, 0);
 625         btrfs_set_root_limit(root_item, 0);
 626         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 627
 628         btrfs_set_root_bytenr(root_item, leaf->start);
 629         btrfs_set_root_generation(root_item, trans->transid);
 630         btrfs_set_root_level(root_item, 0);
 631         btrfs_set_root_refs(root_item, 1);
 632         btrfs_set_root_used(root_item, leaf->len);
 633         btrfs_set_root_last_snapshot(root_item, 0);
 634
 635         btrfs_set_root_generation_v2(root_item,
 636                         btrfs_root_generation(root_item));
 637         uuid_le_gen(&new_uuid);
 638         memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
 639         btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 640         btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 641         root_item->ctime = root_item->otime;
 642         btrfs_set_root_ctransid(root_item, trans->transid);
 643         btrfs_set_root_otransid(root_item, trans->transid);
 644
 645         btrfs_tree_unlock(leaf);
 646         free_extent_buffer(leaf);
 647         leaf = NULL;
 648
 649         btrfs_set_root_dirid(root_item, new_dirid);
 650
 651         key.objectid = objectid;
 652         key.offset = 0;
 653         key.type = BTRFS_ROOT_ITEM_KEY;
 654         ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
 655                                 root_item);
 656         if (ret)
 657                 goto fail;
 658
 659         key.offset = (u64)-1;
 660         new_root = btrfs_read_fs_root_no_name(fs_info, &key);
 661         if (IS_ERR(new_root)) {
 662                 ret = PTR_ERR(new_root);
 663                 btrfs_abort_transaction(trans, ret);
 664                 goto fail;
 665         }
 666
 667         btrfs_record_root_in_trans(trans, new_root);
 668
 669         ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
 670         if (ret) {
 671                 /* We potentially lose an unused inode item here */
 672                 btrfs_abort_transaction(trans, ret);
 673                 goto fail;
 674         }
 675
 676         mutex_lock(&new_root->objectid_mutex);
 677         new_root->highest_objectid = new_dirid;
 678         mutex_unlock(&new_root->objectid_mutex);
 679
 680         /*
 681          * insert the directory item
 682          */
 683         ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
 684         if (ret) {
 685                 btrfs_abort_transaction(trans, ret);
 686                 goto fail;
 687         }
 688
 689         ret = btrfs_insert_dir_item(trans, root,
 690                                     name, namelen, BTRFS_I(dir), &key,
 691                                     BTRFS_FT_DIR, index);
 692         if (ret) {
 693                 btrfs_abort_transaction(trans, ret);
 694                 goto fail;
 695         }
 696
 697         btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
 698         ret = btrfs_update_inode(trans, root, dir);
 699         BUG_ON(ret);
 700
 701         ret = btrfs_add_root_ref(trans, objectid, root->root_key.objectid,
 702                                  btrfs_ino(BTRFS_I(dir)), index, name, namelen);
 703         BUG_ON(ret);
 704
 705         ret = btrfs_uuid_tree_add(trans, root_item->uuid,
 706                                   BTRFS_UUID_KEY_SUBVOL, objectid);
 707         if (ret)
 708                 btrfs_abort_transaction(trans, ret);
 709
 710 fail:
 711         kfree(root_item);
 712         trans->block_rsv = NULL;
 713         trans->bytes_reserved = 0;
 714         btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 715
 716         if (async_transid) {
 717                 *async_transid = trans->transid;
 718                 err = btrfs_commit_transaction_async(trans, 1);
 719                 if (err)
 720                         err = btrfs_commit_transaction(trans);
 721         } else {
 722                 err = btrfs_commit_transaction(trans);
 723         }
 724         if (err && !ret)
 725                 ret = err;
 726
 727         if (!ret) {
 728                 inode = btrfs_lookup_dentry(dir, dentry);
 729                 if (IS_ERR(inode))
 730                         return PTR_ERR(inode);
 731                 d_instantiate(dentry, inode);
 732         }
 733         return ret;
 734
 735 fail_free:
 736         kfree(root_item);
 737         return ret;
 738 }
 739
 740 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 741                            struct dentry *dentry,
 742                            u64 *async_transid, bool readonly,
 743                            struct btrfs_qgroup_inherit *inherit)
 744 {
 745         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 746         struct inode *inode;
 747         struct btrfs_pending_snapshot *pending_snapshot;
 748         struct btrfs_trans_handle *trans;
 749         int ret;
 750
 751         if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
 752                 return -EINVAL;
 753
 754         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
 755         if (!pending_snapshot)
 756                 return -ENOMEM;
 757
 758         pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 759                         GFP_KERNEL);
 760         pending_snapshot->path = btrfs_alloc_path();
 761         if (!pending_snapshot->root_item || !pending_snapshot->path) {
 762                 ret = -ENOMEM;
 763                 goto free_pending;
 764         }
 765
 766         atomic_inc(&root->will_be_snapshotted);
 767         smp_mb__after_atomic();
 768         /* wait for no snapshot writes */
 769         wait_event(root->subv_writers->wait,
 770                    percpu_counter_sum(&root->subv_writers->counter) == 0);
 771
 772         ret = btrfs_start_delalloc_inodes(root);
 773         if (ret)
 774                 goto dec_and_free;
 775
 776         btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
 777
 778         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 779                              BTRFS_BLOCK_RSV_TEMP);
 780         /*
 781          * 1 - parent dir inode
 782          * 2 - dir entries
 783          * 1 - root item
 784          * 2 - root ref/backref
 785          * 1 - root of snapshot
 786          * 1 - UUID item
 787          */
 788         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 789                                         &pending_snapshot->block_rsv, 8,
 790                                         false);
 791         if (ret)
 792                 goto dec_and_free;
 793
 794         pending_snapshot->dentry = dentry;
 795         pending_snapshot->root = root;
 796         pending_snapshot->readonly = readonly;
 797         pending_snapshot->dir = dir;
 798         pending_snapshot->inherit = inherit;
 799
 800         trans = btrfs_start_transaction(root, 0);
 801         if (IS_ERR(trans)) {
 802                 ret = PTR_ERR(trans);
 803                 goto fail;
 804         }
 805
 806         spin_lock(&fs_info->trans_lock);
 807         list_add(&pending_snapshot->list,
 808                  &trans->transaction->pending_snapshots);
 809         spin_unlock(&fs_info->trans_lock);
 810         if (async_transid) {
 811                 *async_transid = trans->transid;
 812                 ret = btrfs_commit_transaction_async(trans, 1);
 813                 if (ret)
 814                         ret = btrfs_commit_transaction(trans);
 815         } else {
 816                 ret = btrfs_commit_transaction(trans);
 817         }
 818         if (ret)
 819                 goto fail;
 820
 821         ret = pending_snapshot->error;
 822         if (ret)
 823                 goto fail;
 824
 825         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 826         if (ret)
 827                 goto fail;
 828
 829         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 830         if (IS_ERR(inode)) {
 831                 ret = PTR_ERR(inode);
 832                 goto fail;
 833         }
 834
 835         d_instantiate(dentry, inode);
 836         ret = 0;
 837 fail:
 838         btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv);
 839 dec_and_free:
 840         if (atomic_dec_and_test(&root->will_be_snapshotted))
 841                 wake_up_var(&root->will_be_snapshotted);
 842 free_pending:
 843         kfree(pending_snapshot->root_item);
 844         btrfs_free_path(pending_snapshot->path);
 845         kfree(pending_snapshot);
 846
 847         return ret;
 848 }
 849
 850 /*  copy of may_delete in fs/namei.c()
 851  *      Check whether we can remove a link victim from directory dir, check
 852  *  whether the type of victim is right.
 853  *  1. We can't do it if dir is read-only (done in permission())
 854  *  2. We should have write and exec permissions on dir
 855  *  3. We can't remove anything from append-only dir
 856  *  4. We can't do anything with immutable dir (done in permission())
 857  *  5. If the sticky bit on dir is set we should either
 858  *      a. be owner of dir, or
 859  *      b. be owner of victim, or
 860  *      c. have CAP_FOWNER capability
 861  *  6. If the victim is append-only or immutable we can't do anything with
 862  *     links pointing to it.
 863  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 864  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 865  *  9. We can't remove a root or mountpoint.
 866  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 867  *     nfs_async_unlink().
 868  */
 869
 870 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 871 {
 872         int error;
 873
 874         if (d_really_is_negative(victim))
 875                 return -ENOENT;
 876
 877         BUG_ON(d_inode(victim->d_parent) != dir);
 878         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 879
 880         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 881         if (error)
 882                 return error;
 883         if (IS_APPEND(dir))
 884                 return -EPERM;
 885         if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
 886             IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
 887                 return -EPERM;
 888         if (isdir) {
 889                 if (!d_is_dir(victim))
 890                         return -ENOTDIR;
 891                 if (IS_ROOT(victim))
 892                         return -EBUSY;
 893         } else if (d_is_dir(victim))
 894                 return -EISDIR;
 895         if (IS_DEADDIR(dir))
 896                 return -ENOENT;
 897         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 898                 return -EBUSY;
 899         return 0;
 900 }
 901
 902 /* copy of may_create in fs/namei.c() */
 903 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 904 {
 905         if (d_really_is_positive(child))
 906                 return -EEXIST;
 907         if (IS_DEADDIR(dir))
 908                 return -ENOENT;
 909         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 910 }
 911
 912 /*
 913  * Create a new subvolume below @parent.  This is largely modeled after
 914  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 915  * inside this filesystem so it's quite a bit simpler.
 916  */
 917 static noinline int btrfs_mksubvol(const struct path *parent,
 918                                    const char *name, int namelen,
 919                                    struct btrfs_root *snap_src,
 920                                    u64 *async_transid, bool readonly,
 921                                    struct btrfs_qgroup_inherit *inherit)
 922 {
 923         struct inode *dir = d_inode(parent->dentry);
 924         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 925         struct dentry *dentry;
 926         int error;
 927
 928         error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 929         if (error == -EINTR)
 930                 return error;
 931
 932         dentry = lookup_one_len(name, parent->dentry, namelen);
 933         error = PTR_ERR(dentry);
 934         if (IS_ERR(dentry))
 935                 goto out_unlock;
 936
 937         error = btrfs_may_create(dir, dentry);
 938         if (error)
 939                 goto out_dput;
 940
 941         /*
 942          * even if this name doesn't exist, we may get hash collisions.
 943          * check for them now when we can safely fail
 944          */
 945         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 946                                                dir->i_ino, name,
 947                                                namelen);
 948         if (error)
 949                 goto out_dput;
 950
 951         down_read(&fs_info->subvol_sem);
 952
 953         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 954                 goto out_up_read;
 955
 956         if (snap_src) {
 957                 error = create_snapshot(snap_src, dir, dentry,
 958                                         async_transid, readonly, inherit);
 959         } else {
 960                 error = create_subvol(dir, dentry, name, namelen,
 961                                       async_transid, inherit);
 962         }
 963         if (!error)
 964                 fsnotify_mkdir(dir, dentry);
 965 out_up_read:
 966         up_read(&fs_info->subvol_sem);
 967 out_dput:
 968         dput(dentry);
 969 out_unlock:
 970         inode_unlock(dir);
 971         return error;
 972 }
 973
 974 /*
 975  * When we're defragging a range, we don't want to kick it off again
 976  * if it is really just waiting for delalloc to send it down.
 977  * If we find a nice big extent or delalloc range for the bytes in the
 978  * file you want to defrag, we return 0 to let you know to skip this
 979  * part of the file
 980  */
 981 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
 982 {
 983         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 984         struct extent_map *em = NULL;
 985         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 986         u64 end;
 987
 988         read_lock(&em_tree->lock);
 989         em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
 990         read_unlock(&em_tree->lock);
 991
 992         if (em) {
 993                 end = extent_map_end(em);
 994                 free_extent_map(em);
 995                 if (end - offset > thresh)
 996                         return 0;
 997         }
 998         /* if we already have a nice delalloc here, just stop */
 999         thresh /= 2;
1000         end = count_range_bits(io_tree, &offset, offset + thresh,
1001                                thresh, EXTENT_DELALLOC, 1);
1002         if (end >= thresh)
1003                 return 0;
1004         return 1;
1005 }
1006
1007 /*
1008  * helper function to walk through a file and find extents
1009  * newer than a specific transid, and smaller than thresh.
1010  *
1011  * This is used by the defragging code to find new and small
1012  * extents
1013  */
1014 static int find_new_extents(struct btrfs_root *root,
1015                             struct inode *inode, u64 newer_than,
1016                             u64 *off, u32 thresh)
1017 {
1018         struct btrfs_path *path;
1019         struct btrfs_key min_key;
1020         struct extent_buffer *leaf;
1021         struct btrfs_file_extent_item *extent;
1022         int type;
1023         int ret;
1024         u64 ino = btrfs_ino(BTRFS_I(inode));
1025
1026         path = btrfs_alloc_path();
1027         if (!path)
1028                 return -ENOMEM;
1029
1030         min_key.objectid = ino;
1031         min_key.type = BTRFS_EXTENT_DATA_KEY;
1032         min_key.offset = *off;
1033
1034         while (1) {
1035                 ret = btrfs_search_forward(root, &min_key, path, newer_than);
1036                 if (ret != 0)
1037                         goto none;
1038 process_slot:
1039                 if (min_key.objectid != ino)
1040                         goto none;
1041                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
1042                         goto none;
1043
1044                 leaf = path->nodes[0];
1045                 extent = btrfs_item_ptr(leaf, path->slots[0],
1046                                         struct btrfs_file_extent_item);
1047
1048                 type = btrfs_file_extent_type(leaf, extent);
1049                 if (type == BTRFS_FILE_EXTENT_REG &&
1050                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
1051                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
1052                         *off = min_key.offset;
1053                         btrfs_free_path(path);
1054                         return 0;
1055                 }
1056
1057                 path->slots[0]++;
1058                 if (path->slots[0] < btrfs_header_nritems(leaf)) {
1059                         btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
1060                         goto process_slot;
1061                 }
1062
1063                 if (min_key.offset == (u64)-1)
1064                         goto none;
1065
1066                 min_key.offset++;
1067                 btrfs_release_path(path);
1068         }
1069 none:
1070         btrfs_free_path(path);
1071         return -ENOENT;
1072 }
1073
1074 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
1075 {
1076         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1077         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1078         struct extent_map *em;
1079         u64 len = PAGE_SIZE;
1080
1081         /*
1082          * hopefully we have this extent in the tree already, try without
1083          * the full extent lock
1084          */
1085         read_lock(&em_tree->lock);
1086         em = lookup_extent_mapping(em_tree, start, len);
1087         read_unlock(&em_tree->lock);
1088
1089         if (!em) {
1090                 struct extent_state *cached = NULL;
1091                 u64 end = start + len - 1;
1092
1093                 /* get the big lock and read metadata off disk */
1094                 lock_extent_bits(io_tree, start, end, &cached);
1095                 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
1096                 unlock_extent_cached(io_tree, start, end, &cached);
1097
1098                 if (IS_ERR(em))
1099                         return NULL;
1100         }
1101
1102         return em;
1103 }
1104
1105 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1106 {
1107         struct extent_map *next;
1108         bool ret = true;
1109
1110         /* this is the last extent */
1111         if (em->start + em->len >= i_size_read(inode))
1112                 return false;
1113
1114         next = defrag_lookup_extent(inode, em->start + em->len);
1115         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1116                 ret = false;
1117         else if ((em->block_start + em->block_len == next->block_start) &&
1118                  (em->block_len > SZ_128K && next->block_len > SZ_128K))
1119                 ret = false;
1120
1121         free_extent_map(next);
1122         return ret;
1123 }
1124
1125 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1126                                u64 *last_len, u64 *skip, u64 *defrag_end,
1127                                int compress)
1128 {
1129         struct extent_map *em;
1130         int ret = 1;
1131         bool next_mergeable = true;
1132         bool prev_mergeable = true;
1133
1134         /*
1135          * make sure that once we start defragging an extent, we keep on
1136          * defragging it
1137          */
1138         if (start < *defrag_end)
1139                 return 1;
1140
1141         *skip = 0;
1142
1143         em = defrag_lookup_extent(inode, start);
1144         if (!em)
1145                 return 0;
1146
1147         /* this will cover holes, and inline extents */
1148         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1149                 ret = 0;
1150                 goto out;
1151         }
1152
1153         if (!*defrag_end)
1154                 prev_mergeable = false;
1155
1156         next_mergeable = defrag_check_next_extent(inode, em);
1157         /*
1158          * we hit a real extent, if it is big or the next extent is not a
1159          * real extent, don't bother defragging it
1160          */
1161         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1162             (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1163                 ret = 0;
1164 out:
1165         /*
1166          * last_len ends up being a counter of how many bytes we've defragged.
1167          * every time we choose not to defrag an extent, we reset *last_len
1168          * so that the next tiny extent will force a defrag.
1169          *
1170          * The end result of this is that tiny extents before a single big
1171          * extent will force at least part of that big extent to be defragged.
1172          */
1173         if (ret) {
1174                 *defrag_end = extent_map_end(em);
1175         } else {
1176                 *last_len = 0;
1177                 *skip = extent_map_end(em);
1178                 *defrag_end = 0;
1179         }
1180
1181         free_extent_map(em);
1182         return ret;
1183 }
1184
1185 /*
1186  * it doesn't do much good to defrag one or two pages
1187  * at a time.  This pulls in a nice chunk of pages
1188  * to COW and defrag.
1189  *
1190  * It also makes sure the delalloc code has enough
1191  * dirty data to avoid making new small extents as part
1192  * of the defrag
1193  *
1194  * It's a good idea to start RA on this range
1195  * before calling this.
1196  */
1197 static int cluster_pages_for_defrag(struct inode *inode,
1198                                     struct page **pages,
1199                                     unsigned long start_index,
1200                                     unsigned long num_pages)
1201 {
1202         unsigned long file_end;
1203         u64 isize = i_size_read(inode);
1204         u64 page_start;
1205         u64 page_end;
1206         u64 page_cnt;
1207         int ret;
1208         int i;
1209         int i_done;
1210         struct btrfs_ordered_extent *ordered;
1211         struct extent_state *cached_state = NULL;
1212         struct extent_io_tree *tree;
1213         struct extent_changeset *data_reserved = NULL;
1214         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1215
1216         file_end = (isize - 1) >> PAGE_SHIFT;
1217         if (!isize || start_index > file_end)
1218                 return 0;
1219
1220         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1221
1222         ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
1223                         start_index << PAGE_SHIFT,
1224                         page_cnt << PAGE_SHIFT);
1225         if (ret)
1226                 return ret;
1227         i_done = 0;
1228         tree = &BTRFS_I(inode)->io_tree;
1229
1230         /* step one, lock all the pages */
1231         for (i = 0; i < page_cnt; i++) {
1232                 struct page *page;
1233 again:
1234                 page = find_or_create_page(inode->i_mapping,
1235                                            start_index + i, mask);
1236                 if (!page)
1237                         break;
1238
1239                 page_start = page_offset(page);
1240                 page_end = page_start + PAGE_SIZE - 1;
1241                 while (1) {
1242                         lock_extent_bits(tree, page_start, page_end,
1243                                          &cached_state);
1244                         ordered = btrfs_lookup_ordered_extent(inode,
1245                                                               page_start);
1246                         unlock_extent_cached(tree, page_start, page_end,
1247                                              &cached_state);
1248                         if (!ordered)
1249                                 break;
1250
1251                         unlock_page(page);
1252                         btrfs_start_ordered_extent(inode, ordered, 1);
1253                         btrfs_put_ordered_extent(ordered);
1254                         lock_page(page);
1255                         /*
1256                          * we unlocked the page above, so we need check if
1257                          * it was released or not.
1258                          */
1259                         if (page->mapping != inode->i_mapping) {
1260                                 unlock_page(page);
1261                                 put_page(page);
1262                                 goto again;
1263                         }
1264                 }
1265
1266                 if (!PageUptodate(page)) {
1267                         btrfs_readpage(NULL, page);
1268                         lock_page(page);
1269                         if (!PageUptodate(page)) {
1270                                 unlock_page(page);
1271                                 put_page(page);
1272                                 ret = -EIO;
1273                                 break;
1274                         }
1275                 }
1276
1277                 if (page->mapping != inode->i_mapping) {
1278                         unlock_page(page);
1279                         put_page(page);
1280                         goto again;
1281                 }
1282
1283                 pages[i] = page;
1284                 i_done++;
1285         }
1286         if (!i_done || ret)
1287                 goto out;
1288
1289         if (!(inode->i_sb->s_flags & SB_ACTIVE))
1290                 goto out;
1291
1292         /*
1293          * so now we have a nice long stream of locked
1294          * and up to date pages, lets wait on them
1295          */
1296         for (i = 0; i < i_done; i++)
1297                 wait_on_page_writeback(pages[i]);
1298
1299         page_start = page_offset(pages[0]);
1300         page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1301
1302         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1303                          page_start, page_end - 1, &cached_state);
1304         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1305                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1306                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1307                           &cached_state);
1308
1309         if (i_done != page_cnt) {
1310                 spin_lock(&BTRFS_I(inode)->lock);
1311                 BTRFS_I(inode)->outstanding_extents++;
1312                 spin_unlock(&BTRFS_I(inode)->lock);
1313                 btrfs_delalloc_release_space(inode, data_reserved,
1314                                 start_index << PAGE_SHIFT,
1315                                 (page_cnt - i_done) << PAGE_SHIFT, true);
1316         }
1317
1318
1319         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1320                           &cached_state);
1321
1322         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1323                              page_start, page_end - 1, &cached_state);
1324
1325         for (i = 0; i < i_done; i++) {
1326                 clear_page_dirty_for_io(pages[i]);
1327                 ClearPageChecked(pages[i]);
1328                 set_page_extent_mapped(pages[i]);
1329                 set_page_dirty(pages[i]);
1330                 unlock_page(pages[i]);
1331                 put_page(pages[i]);
1332         }
1333         btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1334                                        false);
1335         extent_changeset_free(data_reserved);
1336         return i_done;
1337 out:
1338         for (i = 0; i < i_done; i++) {
1339                 unlock_page(pages[i]);
1340                 put_page(pages[i]);
1341         }
1342         btrfs_delalloc_release_space(inode, data_reserved,
1343                         start_index << PAGE_SHIFT,
1344                         page_cnt << PAGE_SHIFT, true);
1345         btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1346                                        true);
1347         extent_changeset_free(data_reserved);
1348         return ret;
1349
1350 }
1351
1352 int btrfs_defrag_file(struct inode *inode, struct file *file,
1353                       struct btrfs_ioctl_defrag_range_args *range,
1354                       u64 newer_than, unsigned long max_to_defrag)
1355 {
1356         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1357         struct btrfs_root *root = BTRFS_I(inode)->root;
1358         struct file_ra_state *ra = NULL;
1359         unsigned long last_index;
1360         u64 isize = i_size_read(inode);
1361         u64 last_len = 0;
1362         u64 skip = 0;
1363         u64 defrag_end = 0;
1364         u64 newer_off = range->start;
1365         unsigned long i;
1366         unsigned long ra_index = 0;
1367         int ret;
1368         int defrag_count = 0;
1369         int compress_type = BTRFS_COMPRESS_ZLIB;
1370         u32 extent_thresh = range->extent_thresh;
1371         unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1372         unsigned long cluster = max_cluster;
1373         u64 new_align = ~((u64)SZ_128K - 1);
1374         struct page **pages = NULL;
1375         bool do_compress = range->flags & BTRFS_DEFRAG_RANGE_COMPRESS;
1376
1377         if (isize == 0)
1378                 return 0;
1379
1380         if (range->start >= isize)
1381                 return -EINVAL;
1382
1383         if (do_compress) {
1384                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1385                         return -EINVAL;
1386                 if (range->compress_type)
1387                         compress_type = range->compress_type;
1388         }
1389
1390         if (extent_thresh == 0)
1391                 extent_thresh = SZ_256K;
1392
1393         /*
1394          * If we were not given a file, allocate a readahead context. As
1395          * readahead is just an optimization, defrag will work without it so
1396          * we don't error out.
1397          */
1398         if (!file) {
1399                 ra = kzalloc(sizeof(*ra), GFP_KERNEL);
1400                 if (ra)
1401                         file_ra_state_init(ra, inode->i_mapping);
1402         } else {
1403                 ra = &file->f_ra;
1404         }
1405
1406         pages = kmalloc_array(max_cluster, sizeof(struct page *), GFP_KERNEL);
1407         if (!pages) {
1408                 ret = -ENOMEM;
1409                 goto out_ra;
1410         }
1411
1412         /* find the last page to defrag */
1413         if (range->start + range->len > range->start) {
1414                 last_index = min_t(u64, isize - 1,
1415                          range->start + range->len - 1) >> PAGE_SHIFT;
1416         } else {
1417                 last_index = (isize - 1) >> PAGE_SHIFT;
1418         }
1419
1420         if (newer_than) {
1421                 ret = find_new_extents(root, inode, newer_than,
1422                                        &newer_off, SZ_64K);
1423                 if (!ret) {
1424                         range->start = newer_off;
1425                         /*
1426                          * we always align our defrag to help keep
1427                          * the extents in the file evenly spaced
1428                          */
1429                         i = (newer_off & new_align) >> PAGE_SHIFT;
1430                 } else
1431                         goto out_ra;
1432         } else {
1433                 i = range->start >> PAGE_SHIFT;
1434         }
1435         if (!max_to_defrag)
1436                 max_to_defrag = last_index - i + 1;
1437
1438         /*
1439          * make writeback starts from i, so the defrag range can be
1440          * written sequentially.
1441          */
1442         if (i < inode->i_mapping->writeback_index)
1443                 inode->i_mapping->writeback_index = i;
1444
1445         while (i <= last_index && defrag_count < max_to_defrag &&
1446                (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1447                 /*
1448                  * make sure we stop running if someone unmounts
1449                  * the FS
1450                  */
1451                 if (!(inode->i_sb->s_flags & SB_ACTIVE))
1452                         break;
1453
1454                 if (btrfs_defrag_cancelled(fs_info)) {
1455                         btrfs_debug(fs_info, "defrag_file cancelled");
1456                         ret = -EAGAIN;
1457                         break;
1458                 }
1459
1460                 if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1461                                          extent_thresh, &last_len, &skip,
1462                                          &defrag_end, do_compress)){
1463                         unsigned long next;
1464                         /*
1465                          * the should_defrag function tells us how much to skip
1466                          * bump our counter by the suggested amount
1467                          */
1468                         next = DIV_ROUND_UP(skip, PAGE_SIZE);
1469                         i = max(i + 1, next);
1470                         continue;
1471                 }
1472
1473                 if (!newer_than) {
1474                         cluster = (PAGE_ALIGN(defrag_end) >>
1475                                    PAGE_SHIFT) - i;
1476                         cluster = min(cluster, max_cluster);
1477                 } else {
1478                         cluster = max_cluster;
1479                 }
1480
1481                 if (i + cluster > ra_index) {
1482                         ra_index = max(i, ra_index);
1483                         if (ra)
1484                                 page_cache_sync_readahead(inode->i_mapping, ra,
1485                                                 file, ra_index, cluster);
1486                         ra_index += cluster;
1487                 }
1488
1489                 inode_lock(inode);
1490                 if (do_compress)
1491                         BTRFS_I(inode)->defrag_compress = compress_type;
1492                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1493                 if (ret < 0) {
1494                         inode_unlock(inode);
1495                         goto out_ra;
1496                 }
1497
1498                 defrag_count += ret;
1499                 balance_dirty_pages_ratelimited(inode->i_mapping);
1500                 inode_unlock(inode);
1501
1502                 if (newer_than) {
1503                         if (newer_off == (u64)-1)
1504                                 break;
1505
1506                         if (ret > 0)
1507                                 i += ret;
1508
1509                         newer_off = max(newer_off + 1,
1510                                         (u64)i << PAGE_SHIFT);
1511
1512                         ret = find_new_extents(root, inode, newer_than,
1513                                                &newer_off, SZ_64K);
1514                         if (!ret) {
1515                                 range->start = newer_off;
1516                                 i = (newer_off & new_align) >> PAGE_SHIFT;
1517                         } else {
1518                                 break;
1519                         }
1520                 } else {
1521                         if (ret > 0) {
1522                                 i += ret;
1523                                 last_len += ret << PAGE_SHIFT;
1524                         } else {
1525                                 i++;
1526                                 last_len = 0;
1527                         }
1528                 }
1529         }
1530
1531         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1532                 filemap_flush(inode->i_mapping);
1533                 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1534                              &BTRFS_I(inode)->runtime_flags))
1535                         filemap_flush(inode->i_mapping);
1536         }
1537
1538         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1539                 btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1540         } else if (range->compress_type == BTRFS_COMPRESS_ZSTD) {
1541                 btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
1542         }
1543
1544         ret = defrag_count;
1545
1546 out_ra:
1547         if (do_compress) {
1548                 inode_lock(inode);
1549                 BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE;
1550                 inode_unlock(inode);
1551         }
1552         if (!file)
1553                 kfree(ra);
1554         kfree(pages);
1555         return ret;
1556 }
1557
1558 static noinline int btrfs_ioctl_resize(struct file *file,
1559                                         void __user *arg)
1560 {
1561         struct inode *inode = file_inode(file);
1562         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1563         u64 new_size;
1564         u64 old_size;
1565         u64 devid = 1;
1566         struct btrfs_root *root = BTRFS_I(inode)->root;
1567         struct btrfs_ioctl_vol_args *vol_args;
1568         struct btrfs_trans_handle *trans;
1569         struct btrfs_device *device = NULL;
1570         char *sizestr;
1571         char *retptr;
1572         char *devstr = NULL;
1573         int ret = 0;
1574         int mod = 0;
1575
1576         if (!capable(CAP_SYS_ADMIN))
1577                 return -EPERM;
1578
1579         ret = mnt_want_write_file(file);
1580         if (ret)
1581                 return ret;
1582
1583         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
1584                 mnt_drop_write_file(file);
1585                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1586         }
1587
1588         vol_args = memdup_user(arg, sizeof(*vol_args));
1589         if (IS_ERR(vol_args)) {
1590                 ret = PTR_ERR(vol_args);
1591                 goto out;
1592         }
1593
1594         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1595
1596         sizestr = vol_args->name;
1597         devstr = strchr(sizestr, ':');
1598         if (devstr) {
1599                 sizestr = devstr + 1;
1600                 *devstr = '\0';
1601                 devstr = vol_args->name;
1602                 ret = kstrtoull(devstr, 10, &devid);
1603                 if (ret)
1604                         goto out_free;
1605                 if (!devid) {
1606                         ret = -EINVAL;
1607                         goto out_free;
1608                 }
1609                 btrfs_info(fs_info, "resizing devid %llu", devid);
1610         }
1611
1612         device = btrfs_find_device(fs_info, devid, NULL, NULL);
1613         if (!device) {
1614                 btrfs_info(fs_info, "resizer unable to find device %llu",
1615                            devid);
1616                 ret = -ENODEV;
1617                 goto out_free;
1618         }
1619
1620         if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1621                 btrfs_info(fs_info,
1622                            "resizer unable to apply on readonly device %llu",
1623                        devid);
1624                 ret = -EPERM;
1625                 goto out_free;
1626         }
1627
1628         if (!strcmp(sizestr, "max"))
1629                 new_size = device->bdev->bd_inode->i_size;
1630         else {
1631                 if (sizestr[0] == '-') {
1632                         mod = -1;
1633                         sizestr++;
1634                 } else if (sizestr[0] == '+') {
1635                         mod = 1;
1636                         sizestr++;
1637                 }
1638                 new_size = memparse(sizestr, &retptr);
1639                 if (*retptr != '\0' || new_size == 0) {
1640                         ret = -EINVAL;
1641                         goto out_free;
1642                 }
1643         }
1644
1645         if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1646                 ret = -EPERM;
1647                 goto out_free;
1648         }
1649
1650         old_size = btrfs_device_get_total_bytes(device);
1651
1652         if (mod < 0) {
1653                 if (new_size > old_size) {
1654                         ret = -EINVAL;
1655                         goto out_free;
1656                 }
1657                 new_size = old_size - new_size;
1658         } else if (mod > 0) {
1659                 if (new_size > ULLONG_MAX - old_size) {
1660                         ret = -ERANGE;
1661                         goto out_free;
1662                 }
1663                 new_size = old_size + new_size;
1664         }
1665
1666         if (new_size < SZ_256M) {
1667                 ret = -EINVAL;
1668                 goto out_free;
1669         }
1670         if (new_size > device->bdev->bd_inode->i_size) {
1671                 ret = -EFBIG;
1672                 goto out_free;
1673         }
1674
1675         new_size = round_down(new_size, fs_info->sectorsize);
1676
1677         btrfs_info_in_rcu(fs_info, "new size for %s is %llu",
1678                           rcu_str_deref(device->name), new_size);
1679
1680         if (new_size > old_size) {
1681                 trans = btrfs_start_transaction(root, 0);
1682                 if (IS_ERR(trans)) {
1683                         ret = PTR_ERR(trans);
1684                         goto out_free;
1685                 }
1686                 ret = btrfs_grow_device(trans, device, new_size);
1687                 btrfs_commit_transaction(trans);
1688         } else if (new_size < old_size) {
1689                 ret = btrfs_shrink_device(device, new_size);
1690         } /* equal, nothing need to do */
1691
1692 out_free:
1693         kfree(vol_args);
1694 out:
1695         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
1696         mnt_drop_write_file(file);
1697         return ret;
1698 }
1699
1700 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1701                                 const char *name, unsigned long fd, int subvol,
1702                                 u64 *transid, bool readonly,
1703                                 struct btrfs_qgroup_inherit *inherit)
1704 {
1705         int namelen;
1706         int ret = 0;
1707
1708         if (!S_ISDIR(file_inode(file)->i_mode))
1709                 return -ENOTDIR;
1710
1711         ret = mnt_want_write_file(file);
1712         if (ret)
1713                 goto out;
1714
1715         namelen = strlen(name);
1716         if (strchr(name, '/')) {
1717                 ret = -EINVAL;
1718                 goto out_drop_write;
1719         }
1720
1721         if (name[0] == '.' &&
1722            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1723                 ret = -EEXIST;
1724                 goto out_drop_write;
1725         }
1726
1727         if (subvol) {
1728                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1729                                      NULL, transid, readonly, inherit);
1730         } else {
1731                 struct fd src = fdget(fd);
1732                 struct inode *src_inode;
1733                 if (!src.file) {
1734                         ret = -EINVAL;
1735                         goto out_drop_write;
1736                 }
1737
1738                 src_inode = file_inode(src.file);
1739                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1740                         btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1741                                    "Snapshot src from another FS");
1742                         ret = -EXDEV;
1743                 } else if (!inode_owner_or_capable(src_inode)) {
1744                         /*
1745                          * Subvolume creation is not restricted, but snapshots
1746                          * are limited to own subvolumes only
1747                          */
1748                         ret = -EPERM;
1749                 } else {
1750                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1751                                              BTRFS_I(src_inode)->root,
1752                                              transid, readonly, inherit);
1753                 }
1754                 fdput(src);
1755         }
1756 out_drop_write:
1757         mnt_drop_write_file(file);
1758 out:
1759         return ret;
1760 }
1761
1762 static noinline int btrfs_ioctl_snap_create(struct file *file,
1763                                             void __user *arg, int subvol)
1764 {
1765         struct btrfs_ioctl_vol_args *vol_args;
1766         int ret;
1767
1768         if (!S_ISDIR(file_inode(file)->i_mode))
1769                 return -ENOTDIR;
1770
1771         vol_args = memdup_user(arg, sizeof(*vol_args));
1772         if (IS_ERR(vol_args))
1773                 return PTR_ERR(vol_args);
1774         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1775
1776         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1777                                               vol_args->fd, subvol,
1778                                               NULL, false, NULL);
1779
1780         kfree(vol_args);
1781         return ret;
1782 }
1783
1784 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1785                                                void __user *arg, int subvol)
1786 {
1787         struct btrfs_ioctl_vol_args_v2 *vol_args;
1788         int ret;
1789         u64 transid = 0;
1790         u64 *ptr = NULL;
1791         bool readonly = false;
1792         struct btrfs_qgroup_inherit *inherit = NULL;
1793
1794         if (!S_ISDIR(file_inode(file)->i_mode))
1795                 return -ENOTDIR;
1796
1797         vol_args = memdup_user(arg, sizeof(*vol_args));
1798         if (IS_ERR(vol_args))
1799                 return PTR_ERR(vol_args);
1800         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1801
1802         if (vol_args->flags &
1803             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1804               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1805                 ret = -EOPNOTSUPP;
1806                 goto free_args;
1807         }
1808
1809         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1810                 ptr = &transid;
1811         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1812                 readonly = true;
1813         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1814                 if (vol_args->size > PAGE_SIZE) {
1815                         ret = -EINVAL;
1816                         goto free_args;
1817                 }
1818                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1819                 if (IS_ERR(inherit)) {
1820                         ret = PTR_ERR(inherit);
1821                         goto free_args;
1822                 }
1823         }
1824
1825         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1826                                               vol_args->fd, subvol, ptr,
1827                                               readonly, inherit);
1828         if (ret)
1829                 goto free_inherit;
1830
1831         if (ptr && copy_to_user(arg +
1832                                 offsetof(struct btrfs_ioctl_vol_args_v2,
1833                                         transid),
1834                                 ptr, sizeof(*ptr)))
1835                 ret = -EFAULT;
1836
1837 free_inherit:
1838         kfree(inherit);
1839 free_args:
1840         kfree(vol_args);
1841         return ret;
1842 }
1843
1844 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1845                                                 void __user *arg)
1846 {
1847         struct inode *inode = file_inode(file);
1848         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1849         struct btrfs_root *root = BTRFS_I(inode)->root;
1850         int ret = 0;
1851         u64 flags = 0;
1852
1853         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1854                 return -EINVAL;
1855
1856         down_read(&fs_info->subvol_sem);
1857         if (btrfs_root_readonly(root))
1858                 flags |= BTRFS_SUBVOL_RDONLY;
1859         up_read(&fs_info->subvol_sem);
1860
1861         if (copy_to_user(arg, &flags, sizeof(flags)))
1862                 ret = -EFAULT;
1863
1864         return ret;
1865 }
1866
1867 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1868                                               void __user *arg)
1869 {
1870         struct inode *inode = file_inode(file);
1871         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1872         struct btrfs_root *root = BTRFS_I(inode)->root;
1873         struct btrfs_trans_handle *trans;
1874         u64 root_flags;
1875         u64 flags;
1876         int ret = 0;
1877
1878         if (!inode_owner_or_capable(inode))
1879                 return -EPERM;
1880
1881         ret = mnt_want_write_file(file);
1882         if (ret)
1883                 goto out;
1884
1885         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1886                 ret = -EINVAL;
1887                 goto out_drop_write;
1888         }
1889
1890         if (copy_from_user(&flags, arg, sizeof(flags))) {
1891                 ret = -EFAULT;
1892                 goto out_drop_write;
1893         }
1894
1895         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1896                 ret = -EINVAL;
1897                 goto out_drop_write;
1898         }
1899
1900         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1901                 ret = -EOPNOTSUPP;
1902                 goto out_drop_write;
1903         }
1904
1905         down_write(&fs_info->subvol_sem);
1906
1907         /* nothing to do */
1908         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1909                 goto out_drop_sem;
1910
1911         root_flags = btrfs_root_flags(&root->root_item);
1912         if (flags & BTRFS_SUBVOL_RDONLY) {
1913                 btrfs_set_root_flags(&root->root_item,
1914                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1915         } else {
1916                 /*
1917                  * Block RO -> RW transition if this subvolume is involved in
1918                  * send
1919                  */
1920                 spin_lock(&root->root_item_lock);
1921                 if (root->send_in_progress == 0) {
1922                         btrfs_set_root_flags(&root->root_item,
1923                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1924                         spin_unlock(&root->root_item_lock);
1925                 } else {
1926                         spin_unlock(&root->root_item_lock);
1927                         btrfs_warn(fs_info,
1928                                    "Attempt to set subvolume %llu read-write during send",
1929                                    root->root_key.objectid);
1930                         ret = -EPERM;
1931                         goto out_drop_sem;
1932                 }
1933         }
1934
1935         trans = btrfs_start_transaction(root, 1);
1936         if (IS_ERR(trans)) {
1937                 ret = PTR_ERR(trans);
1938                 goto out_reset;
1939         }
1940
1941         ret = btrfs_update_root(trans, fs_info->tree_root,
1942                                 &root->root_key, &root->root_item);
1943         if (ret < 0) {
1944                 btrfs_end_transaction(trans);
1945                 goto out_reset;
1946         }
1947
1948         ret = btrfs_commit_transaction(trans);
1949
1950 out_reset:
1951         if (ret)
1952                 btrfs_set_root_flags(&root->root_item, root_flags);
1953 out_drop_sem:
1954         up_write(&fs_info->subvol_sem);
1955 out_drop_write:
1956         mnt_drop_write_file(file);
1957 out:
1958         return ret;
1959 }
1960
1961 static noinline int key_in_sk(struct btrfs_key *key,
1962                               struct btrfs_ioctl_search_key *sk)
1963 {
1964         struct btrfs_key test;
1965         int ret;
1966
1967         test.objectid = sk->min_objectid;
1968         test.type = sk->min_type;
1969         test.offset = sk->min_offset;
1970
1971         ret = btrfs_comp_cpu_keys(key, &test);
1972         if (ret < 0)
1973                 return 0;
1974
1975         test.objectid = sk->max_objectid;
1976         test.type = sk->max_type;
1977         test.offset = sk->max_offset;
1978
1979         ret = btrfs_comp_cpu_keys(key, &test);
1980         if (ret > 0)
1981                 return 0;
1982         return 1;
1983 }
1984
1985 static noinline int copy_to_sk(struct btrfs_path *path,
1986                                struct btrfs_key *key,
1987                                struct btrfs_ioctl_search_key *sk,
1988                                size_t *buf_size,
1989                                char __user *ubuf,
1990                                unsigned long *sk_offset,
1991                                int *num_found)
1992 {
1993         u64 found_transid;
1994         struct extent_buffer *leaf;
1995         struct btrfs_ioctl_search_header sh;
1996         struct btrfs_key test;
1997         unsigned long item_off;
1998         unsigned long item_len;
1999         int nritems;
2000         int i;
2001         int slot;
2002         int ret = 0;
2003
2004         leaf = path->nodes[0];
2005         slot = path->slots[0];
2006         nritems = btrfs_header_nritems(leaf);
2007
2008         if (btrfs_header_generation(leaf) > sk->max_transid) {
2009                 i = nritems;
2010                 goto advance_key;
2011         }
2012         found_transid = btrfs_header_generation(leaf);
2013
2014         for (i = slot; i < nritems; i++) {
2015                 item_off = btrfs_item_ptr_offset(leaf, i);
2016                 item_len = btrfs_item_size_nr(leaf, i);
2017
2018                 btrfs_item_key_to_cpu(leaf, key, i);
2019                 if (!key_in_sk(key, sk))
2020                         continue;
2021
2022                 if (sizeof(sh) + item_len > *buf_size) {
2023                         if (*num_found) {
2024                                 ret = 1;
2025                                 goto out;
2026                         }
2027
2028                         /*
2029                          * return one empty item back for v1, which does not
2030                          * handle -EOVERFLOW
2031                          */
2032
2033                         *buf_size = sizeof(sh) + item_len;
2034                         item_len = 0;
2035                         ret = -EOVERFLOW;
2036                 }
2037
2038                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
2039                         ret = 1;
2040                         goto out;
2041                 }
2042
2043                 sh.objectid = key->objectid;
2044                 sh.offset = key->offset;
2045                 sh.type = key->type;
2046                 sh.len = item_len;
2047                 sh.transid = found_transid;
2048
2049                 /* copy search result header */
2050                 if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
2051                         ret = -EFAULT;
2052                         goto out;
2053                 }
2054
2055                 *sk_offset += sizeof(sh);
2056
2057                 if (item_len) {
2058                         char __user *up = ubuf + *sk_offset;
2059                         /* copy the item */
2060                         if (read_extent_buffer_to_user(leaf, up,
2061                                                        item_off, item_len)) {
2062                                 ret = -EFAULT;
2063                                 goto out;
2064                         }
2065
2066                         *sk_offset += item_len;
2067                 }
2068                 (*num_found)++;
2069
2070                 if (ret) /* -EOVERFLOW from above */
2071                         goto out;
2072
2073                 if (*num_found >= sk->nr_items) {
2074                         ret = 1;
2075                         goto out;
2076                 }
2077         }
2078 advance_key:
2079         ret = 0;
2080         test.objectid = sk->max_objectid;
2081         test.type = sk->max_type;
2082         test.offset = sk->max_offset;
2083         if (btrfs_comp_cpu_keys(key, &test) >= 0)
2084                 ret = 1;
2085         else if (key->offset < (u64)-1)
2086                 key->offset++;
2087         else if (key->type < (u8)-1) {
2088                 key->offset = 0;
2089                 key->type++;
2090         } else if (key->objectid < (u64)-1) {
2091                 key->offset = 0;
2092                 key->type = 0;
2093                 key->objectid++;
2094         } else
2095                 ret = 1;
2096 out:
2097         /*
2098          *  0: all items from this leaf copied, continue with next
2099          *  1: * more items can be copied, but unused buffer is too small
2100          *     * all items were found
2101          *     Either way, it will stops the loop which iterates to the next
2102          *     leaf
2103          *  -EOVERFLOW: item was to large for buffer
2104          *  -EFAULT: could not copy extent buffer back to userspace
2105          */
2106         return ret;
2107 }
2108
2109 static noinline int search_ioctl(struct inode *inode,
2110                                  struct btrfs_ioctl_search_key *sk,
2111                                  size_t *buf_size,
2112                                  char __user *ubuf)
2113 {
2114         struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2115         struct btrfs_root *root;
2116         struct btrfs_key key;
2117         struct btrfs_path *path;
2118         int ret;
2119         int num_found = 0;
2120         unsigned long sk_offset = 0;
2121
2122         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2123                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
2124                 return -EOVERFLOW;
2125         }
2126
2127         path = btrfs_alloc_path();
2128         if (!path)
2129                 return -ENOMEM;
2130
2131         if (sk->tree_id == 0) {
2132                 /* search the root of the inode that was passed */
2133                 root = BTRFS_I(inode)->root;
2134         } else {
2135                 key.objectid = sk->tree_id;
2136                 key.type = BTRFS_ROOT_ITEM_KEY;
2137                 key.offset = (u64)-1;
2138                 root = btrfs_read_fs_root_no_name(info, &key);
2139                 if (IS_ERR(root)) {
2140                         btrfs_free_path(path);
2141                         return PTR_ERR(root);
2142                 }
2143         }
2144
2145         key.objectid = sk->min_objectid;
2146         key.type = sk->min_type;
2147         key.offset = sk->min_offset;
2148
2149         while (1) {
2150                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2151                 if (ret != 0) {
2152                         if (ret > 0)
2153                                 ret = 0;
2154                         goto err;
2155                 }
2156                 ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2157                                  &sk_offset, &num_found);
2158                 btrfs_release_path(path);
2159                 if (ret)
2160                         break;
2161
2162         }
2163         if (ret > 0)
2164                 ret = 0;
2165 err:
2166         sk->nr_items = num_found;
2167         btrfs_free_path(path);
2168         return ret;
2169 }
2170
2171 static noinline int btrfs_ioctl_tree_search(struct file *file,
2172                                            void __user *argp)
2173 {
2174         struct btrfs_ioctl_search_args __user *uargs;
2175         struct btrfs_ioctl_search_key sk;
2176         struct inode *inode;
2177         int ret;
2178         size_t buf_size;
2179
2180         if (!capable(CAP_SYS_ADMIN))
2181                 return -EPERM;
2182
2183         uargs = (struct btrfs_ioctl_search_args __user *)argp;
2184
2185         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2186                 return -EFAULT;
2187
2188         buf_size = sizeof(uargs->buf);
2189
2190         inode = file_inode(file);
2191         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2192
2193         /*
2194          * In the origin implementation an overflow is handled by returning a
2195          * search header with a len of zero, so reset ret.
2196          */
2197         if (ret == -EOVERFLOW)
2198                 ret = 0;
2199
2200         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2201                 ret = -EFAULT;
2202         return ret;
2203 }
2204
2205 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2206                                                void __user *argp)
2207 {
2208         struct btrfs_ioctl_search_args_v2 __user *uarg;
2209         struct btrfs_ioctl_search_args_v2 args;
2210         struct inode *inode;
2211         int ret;
2212         size_t buf_size;
2213         const size_t buf_limit = SZ_16M;
2214
2215         if (!capable(CAP_SYS_ADMIN))
2216                 return -EPERM;
2217
2218         /* copy search header and buffer size */
2219         uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2220         if (copy_from_user(&args, uarg, sizeof(args)))
2221                 return -EFAULT;
2222
2223         buf_size = args.buf_size;
2224
2225         /* limit result size to 16MB */
2226         if (buf_size > buf_limit)
2227                 buf_size = buf_limit;
2228
2229         inode = file_inode(file);
2230         ret = search_ioctl(inode, &args.key, &buf_size,
2231                            (char __user *)(&uarg->buf[0]));
2232         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2233                 ret = -EFAULT;
2234         else if (ret == -EOVERFLOW &&
2235                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2236                 ret = -EFAULT;
2237
2238         return ret;
2239 }
2240
2241 /*
2242  * Search INODE_REFs to identify path name of 'dirid' directory
2243  * in a 'tree_id' tree. and sets path name to 'name'.
2244  */
2245 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2246                                 u64 tree_id, u64 dirid, char *name)
2247 {
2248         struct btrfs_root *root;
2249         struct btrfs_key key;
2250         char *ptr;
2251         int ret = -1;
2252         int slot;
2253         int len;
2254         int total_len = 0;
2255         struct btrfs_inode_ref *iref;
2256         struct extent_buffer *l;
2257         struct btrfs_path *path;
2258
2259         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2260                 name[0]='\0';
2261                 return 0;
2262         }
2263
2264         path = btrfs_alloc_path();
2265         if (!path)
2266                 return -ENOMEM;
2267
2268         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
2269
2270         key.objectid = tree_id;
2271         key.type = BTRFS_ROOT_ITEM_KEY;
2272         key.offset = (u64)-1;
2273         root = btrfs_read_fs_root_no_name(info, &key);
2274         if (IS_ERR(root)) {
2275                 ret = PTR_ERR(root);
2276                 goto out;
2277         }
2278
2279         key.objectid = dirid;
2280         key.type = BTRFS_INODE_REF_KEY;
2281         key.offset = (u64)-1;
2282
2283         while (1) {
2284                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2285                 if (ret < 0)
2286                         goto out;
2287                 else if (ret > 0) {
2288                         ret = btrfs_previous_item(root, path, dirid,
2289                                                   BTRFS_INODE_REF_KEY);
2290                         if (ret < 0)
2291                                 goto out;
2292                         else if (ret > 0) {
2293                                 ret = -ENOENT;
2294                                 goto out;
2295                         }
2296                 }
2297
2298                 l = path->nodes[0];
2299                 slot = path->slots[0];
2300                 btrfs_item_key_to_cpu(l, &key, slot);
2301
2302                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2303                 len = btrfs_inode_ref_name_len(l, iref);
2304                 ptr -= len + 1;
2305                 total_len += len + 1;
2306                 if (ptr < name) {
2307                         ret = -ENAMETOOLONG;
2308                         goto out;
2309                 }
2310
2311                 *(ptr + len) = '/';
2312                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2313
2314                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2315                         break;
2316
2317                 btrfs_release_path(path);
2318                 key.objectid = key.offset;
2319                 key.offset = (u64)-1;
2320                 dirid = key.objectid;
2321         }
2322         memmove(name, ptr, total_len);
2323         name[total_len] = '\0';
2324         ret = 0;
2325 out:
2326         btrfs_free_path(path);
2327         return ret;
2328 }
2329
2330 static int btrfs_search_path_in_tree_user(struct inode *inode,
2331                                 struct btrfs_ioctl_ino_lookup_user_args *args)
2332 {
2333         struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2334         struct super_block *sb = inode->i_sb;
2335         struct btrfs_key upper_limit = BTRFS_I(inode)->location;
2336         u64 treeid = BTRFS_I(inode)->root->root_key.objectid;
2337         u64 dirid = args->dirid;
2338         unsigned long item_off;
2339         unsigned long item_len;
2340         struct btrfs_inode_ref *iref;
2341         struct btrfs_root_ref *rref;
2342         struct btrfs_root *root;
2343         struct btrfs_path *path;
2344         struct btrfs_key key, key2;
2345         struct extent_buffer *leaf;
2346         struct inode *temp_inode;
2347         char *ptr;
2348         int slot;
2349         int len;
2350         int total_len = 0;
2351         int ret;
2352
2353         path = btrfs_alloc_path();
2354         if (!path)
2355                 return -ENOMEM;
2356
2357         /*
2358          * If the bottom subvolume does not exist directly under upper_limit,
2359          * construct the path in from the bottom up.
2360          */
2361         if (dirid != upper_limit.objectid) {
2362                 ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
2363
2364                 key.objectid = treeid;
2365                 key.type = BTRFS_ROOT_ITEM_KEY;
2366                 key.offset = (u64)-1;
2367                 root = btrfs_read_fs_root_no_name(fs_info, &key);
2368                 if (IS_ERR(root)) {
2369                         ret = PTR_ERR(root);
2370                         goto out;
2371                 }
2372
2373                 key.objectid = dirid;
2374                 key.type = BTRFS_INODE_REF_KEY;
2375                 key.offset = (u64)-1;
2376                 while (1) {
2377                         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2378                         if (ret < 0) {
2379                                 goto out;
2380                         } else if (ret > 0) {
2381                                 ret = btrfs_previous_item(root, path, dirid,
2382                                                           BTRFS_INODE_REF_KEY);
2383                                 if (ret < 0) {
2384                                         goto out;
2385                                 } else if (ret > 0) {
2386                                         ret = -ENOENT;
2387                                         goto out;
2388                                 }
2389                         }
2390
2391                         leaf = path->nodes[0];
2392                         slot = path->slots[0];
2393                         btrfs_item_key_to_cpu(leaf, &key, slot);
2394
2395                         iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
2396                         len = btrfs_inode_ref_name_len(leaf, iref);
2397                         ptr -= len + 1;
2398                         total_len += len + 1;
2399                         if (ptr < args->path) {
2400                                 ret = -ENAMETOOLONG;
2401                                 goto out;
2402                         }
2403
2404                         *(ptr + len) = '/';
2405                         read_extent_buffer(leaf, ptr,
2406                                         (unsigned long)(iref + 1), len);
2407
2408                         /* Check the read+exec permission of this directory */
2409                         ret = btrfs_previous_item(root, path, dirid,
2410                                                   BTRFS_INODE_ITEM_KEY);
2411                         if (ret < 0) {
2412                                 goto out;
2413                         } else if (ret > 0) {
2414                                 ret = -ENOENT;
2415                                 goto out;
2416                         }
2417
2418                         leaf = path->nodes[0];
2419                         slot = path->slots[0];
2420                         btrfs_item_key_to_cpu(leaf, &key2, slot);
2421                         if (key2.objectid != dirid) {
2422                                 ret = -ENOENT;
2423                                 goto out;
2424                         }
2425
2426                         temp_inode = btrfs_iget(sb, &key2, root, NULL);
2427                         if (IS_ERR(temp_inode)) {
2428                                 ret = PTR_ERR(temp_inode);
2429                                 goto out;
2430                         }
2431                         ret = inode_permission(temp_inode, MAY_READ | MAY_EXEC);
2432                         iput(temp_inode);
2433                         if (ret) {
2434                                 ret = -EACCES;
2435                                 goto out;
2436                         }
2437
2438                         if (key.offset == upper_limit.objectid)
2439                                 break;
2440                         if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
2441                                 ret = -EACCES;
2442                                 goto out;
2443                         }
2444
2445                         btrfs_release_path(path);
2446                         key.objectid = key.offset;
2447                         key.offset = (u64)-1;
2448                         dirid = key.objectid;
2449                 }
2450
2451                 memmove(args->path, ptr, total_len);
2452                 args->path[total_len] = '\0';
2453                 btrfs_release_path(path);
2454         }
2455
2456         /* Get the bottom subvolume's name from ROOT_REF */
2457         root = fs_info->tree_root;
2458         key.objectid = treeid;
2459         key.type = BTRFS_ROOT_REF_KEY;
2460         key.offset = args->treeid;
2461         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2462         if (ret < 0) {
2463                 goto out;
2464         } else if (ret > 0) {
2465                 ret = -ENOENT;
2466                 goto out;
2467         }
2468
2469         leaf = path->nodes[0];
2470         slot = path->slots[0];
2471         btrfs_item_key_to_cpu(leaf, &key, slot);
2472
2473         item_off = btrfs_item_ptr_offset(leaf, slot);
2474         item_len = btrfs_item_size_nr(leaf, slot);
2475         /* Check if dirid in ROOT_REF corresponds to passed dirid */
2476         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2477         if (args->dirid != btrfs_root_ref_dirid(leaf, rref)) {
2478                 ret = -EINVAL;
2479                 goto out;
2480         }
2481
2482         /* Copy subvolume's name */
2483         item_off += sizeof(struct btrfs_root_ref);
2484         item_len -= sizeof(struct btrfs_root_ref);
2485         read_extent_buffer(leaf, args->name, item_off, item_len);
2486         args->name[item_len] = 0;
2487
2488 out:
2489         btrfs_free_path(path);
2490         return ret;
2491 }
2492
2493 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2494                                            void __user *argp)
2495 {
2496         struct btrfs_ioctl_ino_lookup_args *args;
2497         struct inode *inode;
2498         int ret = 0;
2499
2500         args = memdup_user(argp, sizeof(*args));
2501         if (IS_ERR(args))
2502                 return PTR_ERR(args);
2503
2504         inode = file_inode(file);
2505
2506         /*
2507          * Unprivileged query to obtain the containing subvolume root id. The
2508          * path is reset so it's consistent with btrfs_search_path_in_tree.
2509          */
2510         if (args->treeid == 0)
2511                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2512
2513         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2514                 args->name[0] = 0;
2515                 goto out;
2516         }
2517
2518         if (!capable(CAP_SYS_ADMIN)) {
2519                 ret = -EPERM;
2520                 goto out;
2521         }
2522
2523         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2524                                         args->treeid, args->objectid,
2525                                         args->name);
2526
2527 out:
2528         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2529                 ret = -EFAULT;
2530
2531         kfree(args);
2532         return ret;
2533 }
2534
2535 /*
2536  * Version of ino_lookup ioctl (unprivileged)
2537  *
2538  * The main differences from ino_lookup ioctl are:
2539  *
2540  *   1. Read + Exec permission will be checked using inode_permission() during
2541  *      path construction. -EACCES will be returned in case of failure.
2542  *   2. Path construction will be stopped at the inode number which corresponds
2543  *      to the fd with which this ioctl is called. If constructed path does not
2544  *      exist under fd's inode, -EACCES will be returned.
2545  *   3. The name of bottom subvolume is also searched and filled.
2546  */
2547 static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
2548 {
2549         struct btrfs_ioctl_ino_lookup_user_args *args;
2550         struct inode *inode;
2551         int ret;
2552
2553         args = memdup_user(argp, sizeof(*args));
2554         if (IS_ERR(args))
2555                 return PTR_ERR(args);
2556
2557         inode = file_inode(file);
2558
2559         if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
2560             BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
2561                 /*
2562                  * The subvolume does not exist under fd with which this is
2563                  * called
2564                  */
2565                 kfree(args);
2566                 return -EACCES;
2567         }
2568
2569         ret = btrfs_search_path_in_tree_user(inode, args);
2570
2571         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2572                 ret = -EFAULT;
2573
2574         kfree(args);
2575         return ret;
2576 }
2577
2578 /* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
2579 static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
2580 {
2581         struct btrfs_ioctl_get_subvol_info_args *subvol_info;
2582         struct btrfs_fs_info *fs_info;
2583         struct btrfs_root *root;
2584         struct btrfs_path *path;
2585         struct btrfs_key key;
2586         struct btrfs_root_item *root_item;
2587         struct btrfs_root_ref *rref;
2588         struct extent_buffer *leaf;
2589         unsigned long item_off;
2590         unsigned long item_len;
2591         struct inode *inode;
2592         int slot;
2593         int ret = 0;
2594
2595         path = btrfs_alloc_path();
2596         if (!path)
2597                 return -ENOMEM;
2598
2599         subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
2600         if (!subvol_info) {
2601                 btrfs_free_path(path);
2602                 return -ENOMEM;
2603         }
2604
2605         inode = file_inode(file);
2606         fs_info = BTRFS_I(inode)->root->fs_info;
2607
2608         /* Get root_item of inode's subvolume */
2609         key.objectid = BTRFS_I(inode)->root->root_key.objectid;
2610         key.type = BTRFS_ROOT_ITEM_KEY;
2611         key.offset = (u64)-1;
2612         root = btrfs_read_fs_root_no_name(fs_info, &key);
2613         if (IS_ERR(root)) {
2614                 ret = PTR_ERR(root);
2615                 goto out;
2616         }
2617         root_item = &root->root_item;
2618
2619         subvol_info->treeid = key.objectid;
2620
2621         subvol_info->generation = btrfs_root_generation(root_item);
2622         subvol_info->flags = btrfs_root_flags(root_item);
2623
2624         memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
2625         memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
2626                                                     BTRFS_UUID_SIZE);
2627         memcpy(subvol_info->received_uuid, root_item->received_uuid,
2628                                                     BTRFS_UUID_SIZE);
2629
2630         subvol_info->ctransid = btrfs_root_ctransid(root_item);
2631         subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
2632         subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);
2633
2634         subvol_info->otransid = btrfs_root_otransid(root_item);
2635         subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
2636         subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);
2637
2638         subvol_info->stransid = btrfs_root_stransid(root_item);
2639         subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
2640         subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);
2641
2642         subvol_info->rtransid = btrfs_root_rtransid(root_item);
2643         subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
2644         subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);
2645
2646         if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
2647                 /* Search root tree for ROOT_BACKREF of this subvolume */
2648                 root = fs_info->tree_root;
2649
2650                 key.type = BTRFS_ROOT_BACKREF_KEY;
2651                 key.offset = 0;
2652                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2653                 if (ret < 0) {
2654                         goto out;
2655                 } else if (path->slots[0] >=
2656                            btrfs_header_nritems(path->nodes[0])) {
2657                         ret = btrfs_next_leaf(root, path);
2658                         if (ret < 0) {
2659                                 goto out;
2660                         } else if (ret > 0) {
2661                                 ret = -EUCLEAN;
2662                                 goto out;
2663                         }
2664                 }
2665
2666                 leaf = path->nodes[0];
2667                 slot = path->slots[0];
2668                 btrfs_item_key_to_cpu(leaf, &key, slot);
2669                 if (key.objectid == subvol_info->treeid &&
2670                     key.type == BTRFS_ROOT_BACKREF_KEY) {
2671                         subvol_info->parent_id = key.offset;
2672
2673                         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2674                         subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);
2675
2676                         item_off = btrfs_item_ptr_offset(leaf, slot)
2677                                         + sizeof(struct btrfs_root_ref);
2678                         item_len = btrfs_item_size_nr(leaf, slot)
2679                                         - sizeof(struct btrfs_root_ref);
2680                         read_extent_buffer(leaf, subvol_info->name,
2681                                            item_off, item_len);
2682                 } else {
2683                         ret = -ENOENT;
2684                         goto out;
2685                 }
2686         }
2687
2688         if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
2689                 ret = -EFAULT;
2690
2691 out:
2692         btrfs_free_path(path);
2693         kzfree(subvol_info);
2694         return ret;
2695 }
2696
2697 /*
2698  * Return ROOT_REF information of the subvolume containing this inode
2699  * except the subvolume name.
2700  */
2701 static int btrfs_ioctl_get_subvol_rootref(struct file *file, void __user *argp)
2702 {
2703         struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
2704         struct btrfs_root_ref *rref;
2705         struct btrfs_root *root;
2706         struct btrfs_path *path;
2707         struct btrfs_key key;
2708         struct extent_buffer *leaf;
2709         struct inode *inode;
2710         u64 objectid;
2711         int slot;
2712         int ret;
2713         u8 found;
2714
2715         path = btrfs_alloc_path();
2716         if (!path)
2717                 return -ENOMEM;
2718
2719         rootrefs = memdup_user(argp, sizeof(*rootrefs));
2720         if (IS_ERR(rootrefs)) {
2721                 btrfs_free_path(path);
2722                 return PTR_ERR(rootrefs);
2723         }
2724
2725         inode = file_inode(file);
2726         root = BTRFS_I(inode)->root->fs_info->tree_root;
2727         objectid = BTRFS_I(inode)->root->root_key.objectid;
2728
2729         key.objectid = objectid;
2730         key.type = BTRFS_ROOT_REF_KEY;
2731         key.offset = rootrefs->min_treeid;
2732         found = 0;
2733
2734         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2735         if (ret < 0) {
2736                 goto out;
2737         } else if (path->slots[0] >=
2738                    btrfs_header_nritems(path->nodes[0])) {
2739                 ret = btrfs_next_leaf(root, path);
2740                 if (ret < 0) {
2741                         goto out;
2742                 } else if (ret > 0) {
2743                         ret = -EUCLEAN;
2744                         goto out;
2745                 }
2746         }
2747         while (1) {
2748                 leaf = path->nodes[0];
2749                 slot = path->slots[0];
2750
2751                 btrfs_item_key_to_cpu(leaf, &key, slot);
2752                 if (key.objectid != objectid || key.type != BTRFS_ROOT_REF_KEY) {
2753                         ret = 0;
2754                         goto out;
2755                 }
2756
2757                 if (found == BTRFS_MAX_ROOTREF_BUFFER_NUM) {
2758                         ret = -EOVERFLOW;
2759                         goto out;
2760                 }
2761
2762                 rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2763                 rootrefs->rootref[found].treeid = key.offset;
2764                 rootrefs->rootref[found].dirid =
2765                                   btrfs_root_ref_dirid(leaf, rref);
2766                 found++;
2767
2768                 ret = btrfs_next_item(root, path);
2769                 if (ret < 0) {
2770                         goto out;
2771                 } else if (ret > 0) {
2772                         ret = -EUCLEAN;
2773                         goto out;
2774                 }
2775         }
2776
2777 out:
2778         if (!ret || ret == -EOVERFLOW) {
2779                 rootrefs->num_items = found;
2780                 /* update min_treeid for next search */
2781                 if (found)
2782                         rootrefs->min_treeid =
2783                                 rootrefs->rootref[found - 1].treeid + 1;
2784                 if (copy_to_user(argp, rootrefs, sizeof(*rootrefs)))
2785                         ret = -EFAULT;
2786         }
2787
2788         kfree(rootrefs);
2789         btrfs_free_path(path);
2790
2791         return ret;
2792 }
2793
2794 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2795                                              void __user *arg)
2796 {
2797         struct dentry *parent = file->f_path.dentry;
2798         struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2799         struct dentry *dentry;
2800         struct inode *dir = d_inode(parent);
2801         struct inode *inode;
2802         struct btrfs_root *root = BTRFS_I(dir)->root;
2803         struct btrfs_root *dest = NULL;
2804         struct btrfs_ioctl_vol_args *vol_args;
2805         int namelen;
2806         int err = 0;
2807
2808         if (!S_ISDIR(dir->i_mode))
2809                 return -ENOTDIR;
2810
2811         vol_args = memdup_user(arg, sizeof(*vol_args));
2812         if (IS_ERR(vol_args))
2813                 return PTR_ERR(vol_args);
2814
2815         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2816         namelen = strlen(vol_args->name);
2817         if (strchr(vol_args->name, '/') ||
2818             strncmp(vol_args->name, "..", namelen) == 0) {
2819                 err = -EINVAL;
2820                 goto out;
2821         }
2822
2823         err = mnt_want_write_file(file);
2824         if (err)
2825                 goto out;
2826
2827
2828         err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2829         if (err == -EINTR)
2830                 goto out_drop_write;
2831         dentry = lookup_one_len(vol_args->name, parent, namelen);
2832         if (IS_ERR(dentry)) {
2833                 err = PTR_ERR(dentry);
2834                 goto out_unlock_dir;
2835         }
2836
2837         if (d_really_is_negative(dentry)) {
2838                 err = -ENOENT;
2839                 goto out_dput;
2840         }
2841
2842         inode = d_inode(dentry);
2843         dest = BTRFS_I(inode)->root;
2844         if (!capable(CAP_SYS_ADMIN)) {
2845                 /*
2846                  * Regular user.  Only allow this with a special mount
2847                  * option, when the user has write+exec access to the
2848                  * subvol root, and when rmdir(2) would have been
2849                  * allowed.
2850                  *
2851                  * Note that this is _not_ check that the subvol is
2852                  * empty or doesn't contain data that we wouldn't
2853                  * otherwise be able to delete.
2854                  *
2855                  * Users who want to delete empty subvols should try
2856                  * rmdir(2).
2857                  */
2858                 err = -EPERM;
2859                 if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2860                         goto out_dput;
2861
2862                 /*
2863                  * Do not allow deletion if the parent dir is the same
2864                  * as the dir to be deleted.  That means the ioctl
2865                  * must be called on the dentry referencing the root
2866                  * of the subvol, not a random directory contained
2867                  * within it.
2868                  */
2869                 err = -EINVAL;
2870                 if (root == dest)
2871                         goto out_dput;
2872
2873                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2874                 if (err)
2875                         goto out_dput;
2876         }
2877
2878         /* check if subvolume may be deleted by a user */
2879         err = btrfs_may_delete(dir, dentry, 1);
2880         if (err)
2881                 goto out_dput;
2882
2883         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2884                 err = -EINVAL;
2885                 goto out_dput;
2886         }
2887
2888         inode_lock(inode);
2889         err = btrfs_delete_subvolume(dir, dentry);
2890         inode_unlock(inode);
2891         if (!err)
2892                 d_delete(dentry);
2893
2894 out_dput:
2895         dput(dentry);
2896 out_unlock_dir:
2897         inode_unlock(dir);
2898 out_drop_write:
2899         mnt_drop_write_file(file);
2900 out:
2901         kfree(vol_args);
2902         return err;
2903 }
2904
2905 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2906 {
2907         struct inode *inode = file_inode(file);
2908         struct btrfs_root *root = BTRFS_I(inode)->root;
2909         struct btrfs_ioctl_defrag_range_args *range;
2910         int ret;
2911
2912         ret = mnt_want_write_file(file);
2913         if (ret)
2914                 return ret;
2915
2916         if (btrfs_root_readonly(root)) {
2917                 ret = -EROFS;
2918                 goto out;
2919         }
2920
2921         switch (inode->i_mode & S_IFMT) {
2922         case S_IFDIR:
2923                 if (!capable(CAP_SYS_ADMIN)) {
2924                         ret = -EPERM;
2925                         goto out;
2926                 }
2927                 ret = btrfs_defrag_root(root);
2928                 break;
2929         case S_IFREG:
2930                 /*
2931                  * Note that this does not check the file descriptor for write
2932                  * access. This prevents defragmenting executables that are
2933                  * running and allows defrag on files open in read-only mode.
2934                  */
2935                 if (!capable(CAP_SYS_ADMIN) &&
2936                     inode_permission(inode, MAY_WRITE)) {
2937                         ret = -EPERM;
2938                         goto out;
2939                 }
2940
2941                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2942                 if (!range) {
2943                         ret = -ENOMEM;
2944                         goto out;
2945                 }
2946
2947                 if (argp) {
2948                         if (copy_from_user(range, argp,
2949                                            sizeof(*range))) {
2950                                 ret = -EFAULT;
2951                                 kfree(range);
2952                                 goto out;
2953                         }
2954                         /* compression requires us to start the IO */
2955                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2956                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2957                                 range->extent_thresh = (u32)-1;
2958                         }
2959                 } else {
2960                         /* the rest are all set to zero by kzalloc */
2961                         range->len = (u64)-1;
2962                 }
2963                 ret = btrfs_defrag_file(file_inode(file), file,
2964                                         range, BTRFS_OLDEST_GENERATION, 0);
2965                 if (ret > 0)
2966                         ret = 0;
2967                 kfree(range);
2968                 break;
2969         default:
2970                 ret = -EINVAL;
2971         }
2972 out:
2973         mnt_drop_write_file(file);
2974         return ret;
2975 }
2976
2977 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
2978 {
2979         struct btrfs_ioctl_vol_args *vol_args;
2980         int ret;
2981
2982         if (!capable(CAP_SYS_ADMIN))
2983                 return -EPERM;
2984
2985         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
2986                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2987
2988         vol_args = memdup_user(arg, sizeof(*vol_args));
2989         if (IS_ERR(vol_args)) {
2990                 ret = PTR_ERR(vol_args);
2991                 goto out;
2992         }
2993
2994         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2995         ret = btrfs_init_new_device(fs_info, vol_args->name);
2996
2997         if (!ret)
2998                 btrfs_info(fs_info, "disk added %s", vol_args->name);
2999
3000         kfree(vol_args);
3001 out:
3002         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3003         return ret;
3004 }
3005
3006 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
3007 {
3008         struct inode *inode = file_inode(file);
3009         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3010         struct btrfs_ioctl_vol_args_v2 *vol_args;
3011         int ret;
3012
3013         if (!capable(CAP_SYS_ADMIN))
3014                 return -EPERM;
3015
3016         ret = mnt_want_write_file(file);
3017         if (ret)
3018                 return ret;
3019
3020         vol_args = memdup_user(arg, sizeof(*vol_args));
3021         if (IS_ERR(vol_args)) {
3022                 ret = PTR_ERR(vol_args);
3023                 goto err_drop;
3024         }
3025
3026         /* Check for compatibility reject unknown flags */
3027         if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED) {
3028                 ret = -EOPNOTSUPP;
3029                 goto out;
3030         }
3031
3032         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3033                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3034                 goto out;
3035         }
3036
3037         if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
3038                 ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
3039         } else {
3040                 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
3041                 ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3042         }
3043         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3044
3045         if (!ret) {
3046                 if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
3047                         btrfs_info(fs_info, "device deleted: id %llu",
3048                                         vol_args->devid);
3049                 else
3050                         btrfs_info(fs_info, "device deleted: %s",
3051                                         vol_args->name);
3052         }
3053 out:
3054         kfree(vol_args);
3055 err_drop:
3056         mnt_drop_write_file(file);
3057         return ret;
3058 }
3059
3060 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
3061 {
3062         struct inode *inode = file_inode(file);
3063         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3064         struct btrfs_ioctl_vol_args *vol_args;
3065         int ret;
3066
3067         if (!capable(CAP_SYS_ADMIN))
3068                 return -EPERM;
3069
3070         ret = mnt_want_write_file(file);
3071         if (ret)
3072                 return ret;
3073
3074         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3075                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3076                 goto out_drop_write;
3077         }
3078
3079         vol_args = memdup_user(arg, sizeof(*vol_args));
3080         if (IS_ERR(vol_args)) {
3081                 ret = PTR_ERR(vol_args);
3082                 goto out;
3083         }
3084
3085         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3086         ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3087
3088         if (!ret)
3089                 btrfs_info(fs_info, "disk deleted %s", vol_args->name);
3090         kfree(vol_args);
3091 out:
3092         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3093 out_drop_write:
3094         mnt_drop_write_file(file);
3095
3096         return ret;
3097 }
3098
3099 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
3100                                 void __user *arg)
3101 {
3102         struct btrfs_ioctl_fs_info_args *fi_args;
3103         struct btrfs_device *device;
3104         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
3105         int ret = 0;
3106
3107         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
3108         if (!fi_args)
3109                 return -ENOMEM;
3110
3111         rcu_read_lock();
3112         fi_args->num_devices = fs_devices->num_devices;
3113
3114         list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
3115                 if (device->devid > fi_args->max_id)
3116                         fi_args->max_id = device->devid;
3117         }
3118         rcu_read_unlock();
3119
3120         memcpy(&fi_args->fsid, fs_info->fsid, sizeof(fi_args->fsid));
3121         fi_args->nodesize = fs_info->nodesize;
3122         fi_args->sectorsize = fs_info->sectorsize;
3123         fi_args->clone_alignment = fs_info->sectorsize;
3124
3125         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
3126                 ret = -EFAULT;
3127
3128         kfree(fi_args);
3129         return ret;
3130 }
3131
3132 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
3133                                  void __user *arg)
3134 {
3135         struct btrfs_ioctl_dev_info_args *di_args;
3136         struct btrfs_device *dev;
3137         int ret = 0;
3138         char *s_uuid = NULL;
3139
3140         di_args = memdup_user(arg, sizeof(*di_args));
3141         if (IS_ERR(di_args))
3142                 return PTR_ERR(di_args);
3143
3144         if (!btrfs_is_empty_uuid(di_args->uuid))
3145                 s_uuid = di_args->uuid;
3146
3147         rcu_read_lock();
3148         dev = btrfs_find_device(fs_info, di_args->devid, s_uuid, NULL);
3149
3150         if (!dev) {
3151                 ret = -ENODEV;
3152                 goto out;
3153         }
3154
3155         di_args->devid = dev->devid;
3156         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
3157         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
3158         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
3159         if (dev->name) {
3160                 strncpy(di_args->path, rcu_str_deref(dev->name),
3161                                 sizeof(di_args->path) - 1);
3162                 di_args->path[sizeof(di_args->path) - 1] = 0;
3163         } else {
3164                 di_args->path[0] = '\0';
3165         }
3166
3167 out:
3168         rcu_read_unlock();
3169         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
3170                 ret = -EFAULT;
3171
3172         kfree(di_args);
3173         return ret;
3174 }
3175
3176 static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
3177 {
3178         struct page *page;
3179
3180         page = grab_cache_page(inode->i_mapping, index);
3181         if (!page)
3182                 return ERR_PTR(-ENOMEM);
3183
3184         if (!PageUptodate(page)) {
3185                 int ret;
3186
3187                 ret = btrfs_readpage(NULL, page);
3188                 if (ret)
3189                         return ERR_PTR(ret);
3190                 lock_page(page);
3191                 if (!PageUptodate(page)) {
3192                         unlock_page(page);
3193                         put_page(page);
3194                         return ERR_PTR(-EIO);
3195                 }
3196                 if (page->mapping != inode->i_mapping) {
3197                         unlock_page(page);
3198                         put_page(page);
3199                         return ERR_PTR(-EAGAIN);
3200                 }
3201         }
3202
3203         return page;
3204 }
3205
3206 static int gather_extent_pages(struct inode *inode, struct page **pages,
3207                                int num_pages, u64 off)
3208 {
3209         int i;
3210         pgoff_t index = off >> PAGE_SHIFT;
3211
3212         for (i = 0; i < num_pages; i++) {
3213 again:
3214                 pages[i] = extent_same_get_page(inode, index + i);
3215                 if (IS_ERR(pages[i])) {
3216                         int err = PTR_ERR(pages[i]);
3217
3218                         if (err == -EAGAIN)
3219                                 goto again;
3220                         pages[i] = NULL;
3221                         return err;
3222                 }
3223         }
3224         return 0;
3225 }
3226
3227 static int lock_extent_range(struct inode *inode, u64 off, u64 len,
3228                              bool retry_range_locking)
3229 {
3230         /*
3231          * Do any pending delalloc/csum calculations on inode, one way or
3232          * another, and lock file content.
3233          * The locking order is:
3234          *
3235          *   1) pages
3236          *   2) range in the inode's io tree
3237          */
3238         while (1) {
3239                 struct btrfs_ordered_extent *ordered;
3240                 lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
3241                 ordered = btrfs_lookup_first_ordered_extent(inode,
3242                                                             off + len - 1);
3243                 if ((!ordered ||
3244                      ordered->file_offset + ordered->len <= off ||
3245                      ordered->file_offset >= off + len) &&
3246                     !test_range_bit(&BTRFS_I(inode)->io_tree, off,
3247                                     off + len - 1, EXTENT_DELALLOC, 0, NULL)) {
3248                         if (ordered)
3249                                 btrfs_put_ordered_extent(ordered);
3250                         break;
3251                 }
3252                 unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
3253                 if (ordered)
3254                         btrfs_put_ordered_extent(ordered);
3255                 if (!retry_range_locking)
3256                         return -EAGAIN;
3257                 btrfs_wait_ordered_range(inode, off, len);
3258         }
3259         return 0;
3260 }
3261
3262 static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
3263 {
3264         inode_unlock(inode1);
3265         inode_unlock(inode2);
3266 }
3267
3268 static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
3269 {
3270         if (inode1 < inode2)
3271                 swap(inode1, inode2);
3272
3273         inode_lock_nested(inode1, I_MUTEX_PARENT);
3274         inode_lock_nested(inode2, I_MUTEX_CHILD);
3275 }
3276
3277 static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
3278                                       struct inode *inode2, u64 loff2, u64 len)
3279 {
3280         unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
3281         unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
3282 }
3283
3284 static int btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
3285                                     struct inode *inode2, u64 loff2, u64 len,
3286                                     bool retry_range_locking)
3287 {
3288         int ret;
3289
3290         if (inode1 < inode2) {
3291                 swap(inode1, inode2);
3292                 swap(loff1, loff2);
3293         }
3294         ret = lock_extent_range(inode1, loff1, len, retry_range_locking);
3295         if (ret)
3296                 return ret;
3297         ret = lock_extent_range(inode2, loff2, len, retry_range_locking);
3298         if (ret)
3299                 unlock_extent(&BTRFS_I(inode1)->io_tree, loff1,
3300                               loff1 + len - 1);
3301         return ret;
3302 }
3303
3304 struct cmp_pages {
3305         int             num_pages;
3306         struct page     **src_pages;
3307         struct page     **dst_pages;
3308 };
3309
3310 static void btrfs_cmp_data_free(struct cmp_pages *cmp)
3311 {
3312         int i;
3313         struct page *pg;
3314
3315         for (i = 0; i < cmp->num_pages; i++) {
3316                 pg = cmp->src_pages[i];
3317                 if (pg) {
3318                         unlock_page(pg);
3319                         put_page(pg);
3320                         cmp->src_pages[i] = NULL;
3321                 }
3322                 pg = cmp->dst_pages[i];
3323                 if (pg) {
3324                         unlock_page(pg);
3325                         put_page(pg);
3326                         cmp->dst_pages[i] = NULL;
3327                 }
3328         }
3329 }
3330
3331 static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
3332                                   struct inode *dst, u64 dst_loff,
3333                                   u64 len, struct cmp_pages *cmp)
3334 {
3335         int ret;
3336         int num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
3337
3338         cmp->num_pages = num_pages;
3339
3340         ret = gather_extent_pages(src, cmp->src_pages, num_pages, loff);
3341         if (ret)
3342                 goto out;
3343
3344         ret = gather_extent_pages(dst, cmp->dst_pages, num_pages, dst_loff);
3345
3346 out:
3347         if (ret)
3348                 btrfs_cmp_data_free(cmp);
3349         return ret;
3350 }
3351
3352 static int btrfs_cmp_data(u64 len, struct cmp_pages *cmp)
3353 {
3354         int ret = 0;
3355         int i;
3356         struct page *src_page, *dst_page;
3357         unsigned int cmp_len = PAGE_SIZE;
3358         void *addr, *dst_addr;
3359
3360         i = 0;
3361         while (len) {
3362                 if (len < PAGE_SIZE)
3363                         cmp_len = len;
3364
3365                 BUG_ON(i >= cmp->num_pages);
3366
3367                 src_page = cmp->src_pages[i];
3368                 dst_page = cmp->dst_pages[i];
3369                 ASSERT(PageLocked(src_page));
3370                 ASSERT(PageLocked(dst_page));
3371
3372                 addr = kmap_atomic(src_page);
3373                 dst_addr = kmap_atomic(dst_page);
3374
3375                 flush_dcache_page(src_page);
3376                 flush_dcache_page(dst_page);
3377
3378                 if (memcmp(addr, dst_addr, cmp_len))
3379                         ret = -EBADE;
3380
3381                 kunmap_atomic(addr);
3382                 kunmap_atomic(dst_addr);
3383
3384                 if (ret)
3385                         break;
3386
3387                 len -= cmp_len;
3388                 i++;
3389         }
3390
3391         return ret;
3392 }
3393
3394 static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
3395                                      u64 olen)
3396 {
3397         u64 len = *plen;
3398         u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
3399
3400         if (off + olen > inode->i_size || off + olen < off)
3401                 return -EINVAL;
3402
3403         /* if we extend to eof, continue to block boundary */
3404         if (off + len == inode->i_size)
3405                 *plen = len = ALIGN(inode->i_size, bs) - off;
3406
3407         /* Check that we are block aligned - btrfs_clone() requires this */
3408         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
3409                 return -EINVAL;
3410
3411         return 0;
3412 }
3413
3414 static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 olen,
3415                                    struct inode *dst, u64 dst_loff,
3416                                    struct cmp_pages *cmp)
3417 {
3418         int ret;
3419         u64 len = olen;
3420         bool same_inode = (src == dst);
3421         u64 same_lock_start = 0;
3422         u64 same_lock_len = 0;
3423
3424         ret = extent_same_check_offsets(src, loff, &len, olen);
3425         if (ret)
3426                 return ret;
3427
3428         ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
3429         if (ret)
3430                 return ret;
3431
3432         if (same_inode) {
3433                 /*
3434                  * Single inode case wants the same checks, except we
3435                  * don't want our length pushed out past i_size as
3436                  * comparing that data range makes no sense.
3437                  *
3438                  * extent_same_check_offsets() will do this for an
3439                  * unaligned length at i_size, so catch it here and
3440                  * reject the request.
3441                  *
3442                  * This effectively means we require aligned extents
3443                  * for the single-inode case, whereas the other cases
3444                  * allow an unaligned length so long as it ends at
3445                  * i_size.
3446                  */
3447                 if (len != olen)
3448                         return -EINVAL;
3449
3450                 /* Check for overlapping ranges */
3451                 if (dst_loff + len > loff && dst_loff < loff + len)
3452                         return -EINVAL;
3453
3454                 same_lock_start = min_t(u64, loff, dst_loff);
3455                 same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
3456         }
3457
3458 again:
3459         ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, cmp);
3460         if (ret)
3461                 return ret;
3462
3463         if (same_inode)
3464                 ret = lock_extent_range(src, same_lock_start, same_lock_len,
3465                                         false);
3466         else
3467                 ret = btrfs_double_extent_lock(src, loff, dst, dst_loff, len,
3468                                                false);
3469         /*
3470          * If one of the inodes has dirty pages in the respective range or
3471          * ordered extents, we need to flush dellaloc and wait for all ordered
3472          * extents in the range. We must unlock the pages and the ranges in the
3473          * io trees to avoid deadlocks when flushing delalloc (requires locking
3474          * pages) and when waiting for ordered extents to complete (they require
3475          * range locking).
3476          */
3477         if (ret == -EAGAIN) {
3478                 /*
3479                  * Ranges in the io trees already unlocked. Now unlock all
3480                  * pages before waiting for all IO to complete.
3481                  */
3482                 btrfs_cmp_data_free(cmp);
3483                 if (same_inode) {
3484                         btrfs_wait_ordered_range(src, same_lock_start,
3485                                                  same_lock_len);
3486                 } else {
3487                         btrfs_wait_ordered_range(src, loff, len);
3488                         btrfs_wait_ordered_range(dst, dst_loff, len);
3489                 }
3490                 goto again;
3491         }
3492         ASSERT(ret == 0);
3493         if (WARN_ON(ret)) {
3494                 /* ranges in the io trees already unlocked */
3495                 btrfs_cmp_data_free(cmp);
3496                 return ret;
3497         }
3498
3499         /* pass original length for comparison so we stay within i_size */
3500         ret = btrfs_cmp_data(olen, cmp);
3501         if (ret == 0)
3502                 ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
3503
3504         if (same_inode)
3505                 unlock_extent(&BTRFS_I(src)->io_tree, same_lock_start,
3506                               same_lock_start + same_lock_len - 1);
3507         else
3508                 btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
3509
3510         btrfs_cmp_data_free(cmp);
3511
3512         return ret;
3513 }
3514
3515 #define BTRFS_MAX_DEDUPE_LEN    SZ_16M
3516
3517 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
3518                              struct inode *dst, u64 dst_loff)
3519 {
3520         int ret;
3521         struct cmp_pages cmp;
3522         int num_pages = PAGE_ALIGN(BTRFS_MAX_DEDUPE_LEN) >> PAGE_SHIFT;
3523         bool same_inode = (src == dst);
3524         u64 i, tail_len, chunk_count;
3525
3526         if (olen == 0)
3527                 return 0;
3528
3529         if (same_inode)
3530                 inode_lock(src);
3531         else
3532                 btrfs_double_inode_lock(src, dst);
3533
3534         /* don't make the dst file partly checksummed */
3535         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3536             (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
3537                 ret = -EINVAL;
3538                 goto out_unlock;
3539         }
3540
3541         tail_len = olen % BTRFS_MAX_DEDUPE_LEN;
3542         chunk_count = div_u64(olen, BTRFS_MAX_DEDUPE_LEN);
3543         if (chunk_count == 0)
3544                 num_pages = PAGE_ALIGN(tail_len) >> PAGE_SHIFT;
3545
3546         /*
3547          * If deduping ranges in the same inode, locking rules make it
3548          * mandatory to always lock pages in ascending order to avoid deadlocks
3549          * with concurrent tasks (such as starting writeback/delalloc).
3550          */
3551         if (same_inode && dst_loff < loff)
3552                 swap(loff, dst_loff);
3553
3554         /*
3555          * We must gather up all the pages before we initiate our extent
3556          * locking. We use an array for the page pointers. Size of the array is
3557          * bounded by len, which is in turn bounded by BTRFS_MAX_DEDUPE_LEN.
3558          */
3559         cmp.src_pages = kvmalloc_array(num_pages, sizeof(struct page *),
3560                                        GFP_KERNEL | __GFP_ZERO);
3561         cmp.dst_pages = kvmalloc_array(num_pages, sizeof(struct page *),
3562                                        GFP_KERNEL | __GFP_ZERO);
3563         if (!cmp.src_pages || !cmp.dst_pages) {
3564                 ret = -ENOMEM;
3565                 goto out_free;
3566         }
3567
3568         for (i = 0; i < chunk_count; i++) {
3569                 ret = btrfs_extent_same_range(src, loff, BTRFS_MAX_DEDUPE_LEN,
3570                                               dst, dst_loff, &cmp);
3571                 if (ret)
3572                         goto out_free;
3573
3574                 loff += BTRFS_MAX_DEDUPE_LEN;
3575                 dst_loff += BTRFS_MAX_DEDUPE_LEN;
3576         }
3577
3578         if (tail_len > 0)
3579                 ret = btrfs_extent_same_range(src, loff, tail_len, dst,
3580                                               dst_loff, &cmp);
3581
3582 out_free:
3583         kvfree(cmp.src_pages);
3584         kvfree(cmp.dst_pages);
3585
3586 out_unlock:
3587         if (same_inode)
3588                 inode_unlock(src);
3589         else
3590                 btrfs_double_inode_unlock(src, dst);
3591
3592         return ret;
3593 }
3594
3595 int btrfs_dedupe_file_range(struct file *src_file, loff_t src_loff,
3596                             struct file *dst_file, loff_t dst_loff,
3597                             u64 olen)
3598 {
3599         struct inode *src = file_inode(src_file);
3600         struct inode *dst = file_inode(dst_file);
3601         u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
3602
3603         if (WARN_ON_ONCE(bs < PAGE_SIZE)) {
3604                 /*
3605                  * Btrfs does not support blocksize < page_size. As a
3606                  * result, btrfs_cmp_data() won't correctly handle
3607                  * this situation without an update.
3608                  */
3609                 return -EINVAL;
3610         }
3611
3612         return btrfs_extent_same(src, src_loff, olen, dst, dst_loff);
3613 }
3614
3615 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3616                                      struct inode *inode,
3617                                      u64 endoff,
3618                                      const u64 destoff,
3619                                      const u64 olen,
3620                                      int no_time_update)
3621 {
3622         struct btrfs_root *root = BTRFS_I(inode)->root;
3623         int ret;
3624
3625         inode_inc_iversion(inode);
3626         if (!no_time_update)
3627                 inode->i_mtime = inode->i_ctime = current_time(inode);
3628         /*
3629          * We round up to the block size at eof when determining which
3630          * extents to clone above, but shouldn't round up the file size.
3631          */
3632         if (endoff > destoff + olen)
3633                 endoff = destoff + olen;
3634         if (endoff > inode->i_size)
3635                 btrfs_i_size_write(BTRFS_I(inode), endoff);
3636
3637         ret = btrfs_update_inode(trans, root, inode);
3638         if (ret) {
3639                 btrfs_abort_transaction(trans, ret);
3640                 btrfs_end_transaction(trans);
3641                 goto out;
3642         }
3643         ret = btrfs_end_transaction(trans);
3644 out:
3645         return ret;
3646 }
3647
3648 static void clone_update_extent_map(struct btrfs_inode *inode,
3649                                     const struct btrfs_trans_handle *trans,
3650                                     const struct btrfs_path *path,
3651                                     const u64 hole_offset,
3652                                     const u64 hole_len)
3653 {
3654         struct extent_map_tree *em_tree = &inode->extent_tree;
3655         struct extent_map *em;
3656         int ret;
3657
3658         em = alloc_extent_map();
3659         if (!em) {
3660                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3661                 return;
3662         }
3663
3664         if (path) {
3665                 struct btrfs_file_extent_item *fi;
3666
3667                 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3668                                     struct btrfs_file_extent_item);
3669                 btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3670                 em->generation = -1;
3671                 if (btrfs_file_extent_type(path->nodes[0], fi) ==
3672                     BTRFS_FILE_EXTENT_INLINE)
3673                         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3674                                         &inode->runtime_flags);
3675         } else {
3676                 em->start = hole_offset;
3677                 em->len = hole_len;
3678                 em->ram_bytes = em->len;
3679                 em->orig_start = hole_offset;
3680                 em->block_start = EXTENT_MAP_HOLE;
3681                 em->block_len = 0;
3682                 em->orig_block_len = 0;
3683                 em->compress_type = BTRFS_COMPRESS_NONE;
3684                 em->generation = trans->transid;
3685         }
3686
3687         while (1) {
3688                 write_lock(&em_tree->lock);
3689                 ret = add_extent_mapping(em_tree, em, 1);
3690                 write_unlock(&em_tree->lock);
3691                 if (ret != -EEXIST) {
3692                         free_extent_map(em);
3693                         break;
3694                 }
3695                 btrfs_drop_extent_cache(inode, em->start,
3696                                         em->start + em->len - 1, 0);
3697         }
3698
3699         if (ret)
3700                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3701 }
3702
3703 /*
3704  * Make sure we do not end up inserting an inline extent into a file that has
3705  * already other (non-inline) extents. If a file has an inline extent it can
3706  * not have any other extents and the (single) inline extent must start at the
3707  * file offset 0. Failing to respect these rules will lead to file corruption,
3708  * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3709  *
3710  * We can have extents that have been already written to disk or we can have
3711  * dirty ranges still in delalloc, in which case the extent maps and items are
3712  * created only when we run delalloc, and the delalloc ranges might fall outside
3713  * the range we are currently locking in the inode's io tree. So we check the
3714  * inode's i_size because of that (i_size updates are done while holding the
3715  * i_mutex, which we are holding here).
3716  * We also check to see if the inode has a size not greater than "datal" but has
3717  * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3718  * protected against such concurrent fallocate calls by the i_mutex).
3719  *
3720  * If the file has no extents but a size greater than datal, do not allow the
3721  * copy because we would need turn the inline extent into a non-inline one (even
3722  * with NO_HOLES enabled). If we find our destination inode only has one inline
3723  * extent, just overwrite it with the source inline extent if its size is less
3724  * than the source extent's size, or we could copy the source inline extent's
3725  * data into the destination inode's inline extent if the later is greater then
3726  * the former.
3727  */
3728 static int clone_copy_inline_extent(struct inode *dst,
3729                                     struct btrfs_trans_handle *trans,
3730                                     struct btrfs_path *path,
3731                                     struct btrfs_key *new_key,
3732                                     const u64 drop_start,
3733                                     const u64 datal,
3734                                     const u64 skip,
3735                                     const u64 size,
3736                                     char *inline_data)
3737 {
3738         struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
3739         struct btrfs_root *root = BTRFS_I(dst)->root;
3740         const u64 aligned_end = ALIGN(new_key->offset + datal,
3741                                       fs_info->sectorsize);
3742         int ret;
3743         struct btrfs_key key;
3744
3745         if (new_key->offset > 0)
3746                 return -EOPNOTSUPP;
3747
3748         key.objectid = btrfs_ino(BTRFS_I(dst));
3749         key.type = BTRFS_EXTENT_DATA_KEY;
3750         key.offset = 0;
3751         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3752         if (ret < 0) {
3753                 return ret;
3754         } else if (ret > 0) {
3755                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3756                         ret = btrfs_next_leaf(root, path);
3757                         if (ret < 0)
3758                                 return ret;
3759                         else if (ret > 0)
3760                                 goto copy_inline_extent;
3761                 }
3762                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3763                 if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3764                     key.type == BTRFS_EXTENT_DATA_KEY) {
3765                         ASSERT(key.offset > 0);
3766                         return -EOPNOTSUPP;
3767                 }
3768         } else if (i_size_read(dst) <= datal) {
3769                 struct btrfs_file_extent_item *ei;
3770                 u64 ext_len;
3771
3772                 /*
3773                  * If the file size is <= datal, make sure there are no other
3774                  * extents following (can happen do to an fallocate call with
3775                  * the flag FALLOC_FL_KEEP_SIZE).
3776                  */
3777                 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3778                                     struct btrfs_file_extent_item);
3779                 /*
3780                  * If it's an inline extent, it can not have other extents
3781                  * following it.
3782                  */
3783                 if (btrfs_file_extent_type(path->nodes[0], ei) ==
3784                     BTRFS_FILE_EXTENT_INLINE)
3785                         goto copy_inline_extent;
3786
3787                 ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3788                 if (ext_len > aligned_end)
3789                         return -EOPNOTSUPP;
3790
3791                 ret = btrfs_next_item(root, path);
3792                 if (ret < 0) {
3793                         return ret;
3794                 } else if (ret == 0) {
3795                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3796                                               path->slots[0]);
3797                         if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3798                             key.type == BTRFS_EXTENT_DATA_KEY)
3799                                 return -EOPNOTSUPP;
3800                 }
3801         }
3802
3803 copy_inline_extent:
3804         /*
3805          * We have no extent items, or we have an extent at offset 0 which may
3806          * or may not be inlined. All these cases are dealt the same way.
3807          */
3808         if (i_size_read(dst) > datal) {
3809                 /*
3810                  * If the destination inode has an inline extent...
3811                  * This would require copying the data from the source inline
3812                  * extent into the beginning of the destination's inline extent.
3813                  * But this is really complex, both extents can be compressed
3814                  * or just one of them, which would require decompressing and
3815                  * re-compressing data (which could increase the new compressed
3816                  * size, not allowing the compressed data to fit anymore in an
3817                  * inline extent).
3818                  * So just don't support this case for now (it should be rare,
3819                  * we are not really saving space when cloning inline extents).
3820                  */
3821                 return -EOPNOTSUPP;
3822         }
3823
3824         btrfs_release_path(path);
3825         ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3826         if (ret)
3827                 return ret;
3828         ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3829         if (ret)
3830                 return ret;
3831
3832         if (skip) {
3833                 const u32 start = btrfs_file_extent_calc_inline_size(0);
3834
3835                 memmove(inline_data + start, inline_data + start + skip, datal);
3836         }
3837
3838         write_extent_buffer(path->nodes[0], inline_data,
3839                             btrfs_item_ptr_offset(path->nodes[0],
3840                                                   path->slots[0]),
3841                             size);
3842         inode_add_bytes(dst, datal);
3843
3844         return 0;
3845 }
3846
3847 /**
3848  * btrfs_clone() - clone a range from inode file to another
3849  *
3850  * @src: Inode to clone from
3851  * @inode: Inode to clone to
3852  * @off: Offset within source to start clone from
3853  * @olen: Original length, passed by user, of range to clone
3854  * @olen_aligned: Block-aligned value of olen
3855  * @destoff: Offset within @inode to start clone
3856  * @no_time_update: Whether to update mtime/ctime on the target inode
3857  */
3858 static int btrfs_clone(struct inode *src, struct inode *inode,
3859                        const u64 off, const u64 olen, const u64 olen_aligned,
3860                        const u64 destoff, int no_time_update)
3861 {
3862         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3863         struct btrfs_root *root = BTRFS_I(inode)->root;
3864         struct btrfs_path *path = NULL;
3865         struct extent_buffer *leaf;
3866         struct btrfs_trans_handle *trans;
3867         char *buf = NULL;
3868         struct btrfs_key key;
3869         u32 nritems;
3870         int slot;
3871         int ret;
3872         const u64 len = olen_aligned;
3873         u64 last_dest_end = destoff;
3874
3875         ret = -ENOMEM;
3876         buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
3877         if (!buf)
3878                 return ret;
3879
3880         path = btrfs_alloc_path();
3881         if (!path) {
3882                 kvfree(buf);
3883                 return ret;
3884         }
3885
3886         path->reada = READA_FORWARD;
3887         /* clone data */
3888         key.objectid = btrfs_ino(BTRFS_I(src));
3889         key.type = BTRFS_EXTENT_DATA_KEY;
3890         key.offset = off;
3891
3892         while (1) {
3893                 u64 next_key_min_offset = key.offset + 1;
3894
3895                 /*
3896                  * note the key will change type as we walk through the
3897                  * tree.
3898                  */
3899                 path->leave_spinning = 1;
3900                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3901                                 0, 0);
3902                 if (ret < 0)
3903                         goto out;
3904                 /*
3905                  * First search, if no extent item that starts at offset off was
3906                  * found but the previous item is an extent item, it's possible
3907                  * it might overlap our target range, therefore process it.
3908                  */
3909                 if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3910                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3911                                               path->slots[0] - 1);
3912                         if (key.type == BTRFS_EXTENT_DATA_KEY)
3913                                 path->slots[0]--;
3914                 }
3915
3916                 nritems = btrfs_header_nritems(path->nodes[0]);
3917 process_slot:
3918                 if (path->slots[0] >= nritems) {
3919                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3920                         if (ret < 0)
3921                                 goto out;
3922                         if (ret > 0)
3923                                 break;
3924                         nritems = btrfs_header_nritems(path->nodes[0]);
3925                 }
3926                 leaf = path->nodes[0];
3927                 slot = path->slots[0];
3928
3929                 btrfs_item_key_to_cpu(leaf, &key, slot);
3930                 if (key.type > BTRFS_EXTENT_DATA_KEY ||
3931                     key.objectid != btrfs_ino(BTRFS_I(src)))
3932                         break;
3933
3934                 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3935                         struct btrfs_file_extent_item *extent;
3936                         int type;
3937                         u32 size;
3938                         struct btrfs_key new_key;
3939                         u64 disko = 0, diskl = 0;
3940                         u64 datao = 0, datal = 0;
3941                         u8 comp;
3942                         u64 drop_start;
3943
3944                         extent = btrfs_item_ptr(leaf, slot,
3945                                                 struct btrfs_file_extent_item);
3946                         comp = btrfs_file_extent_compression(leaf, extent);
3947                         type = btrfs_file_extent_type(leaf, extent);
3948                         if (type == BTRFS_FILE_EXTENT_REG ||
3949                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3950                                 disko = btrfs_file_extent_disk_bytenr(leaf,
3951                                                                       extent);
3952                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
3953                                                                  extent);
3954                                 datao = btrfs_file_extent_offset(leaf, extent);
3955                                 datal = btrfs_file_extent_num_bytes(leaf,
3956                                                                     extent);
3957                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3958                                 /* take upper bound, may be compressed */
3959                                 datal = btrfs_file_extent_ram_bytes(leaf,
3960                                                                     extent);
3961                         }
3962
3963                         /*
3964                          * The first search might have left us at an extent
3965                          * item that ends before our target range's start, can
3966                          * happen if we have holes and NO_HOLES feature enabled.
3967                          */
3968                         if (key.offset + datal <= off) {
3969                                 path->slots[0]++;
3970                                 goto process_slot;
3971                         } else if (key.offset >= off + len) {
3972                                 break;
3973                         }
3974                         next_key_min_offset = key.offset + datal;
3975                         size = btrfs_item_size_nr(leaf, slot);
3976                         read_extent_buffer(leaf, buf,
3977                                            btrfs_item_ptr_offset(leaf, slot),
3978                                            size);
3979
3980                         btrfs_release_path(path);
3981                         path->leave_spinning = 0;
3982
3983                         memcpy(&new_key, &key, sizeof(new_key));
3984                         new_key.objectid = btrfs_ino(BTRFS_I(inode));
3985                         if (off <= key.offset)
3986                                 new_key.offset = key.offset + destoff - off;
3987                         else
3988                                 new_key.offset = destoff;
3989
3990                         /*
3991                          * Deal with a hole that doesn't have an extent item
3992                          * that represents it (NO_HOLES feature enabled).
3993                          * This hole is either in the middle of the cloning
3994                          * range or at the beginning (fully overlaps it or
3995                          * partially overlaps it).
3996                          */
3997                         if (new_key.offset != last_dest_end)
3998                                 drop_start = last_dest_end;
3999                         else
4000                                 drop_start = new_key.offset;
4001
4002                         /*
4003                          * 1 - adjusting old extent (we may have to split it)
4004                          * 1 - add new extent
4005                          * 1 - inode update
4006                          */
4007                         trans = btrfs_start_transaction(root, 3);
4008                         if (IS_ERR(trans)) {
4009                                 ret = PTR_ERR(trans);
4010                                 goto out;
4011                         }
4012
4013                         if (type == BTRFS_FILE_EXTENT_REG ||
4014                             type == BTRFS_FILE_EXTENT_PREALLOC) {
4015                                 /*
4016                                  *    a  | --- range to clone ---|  b
4017                                  * | ------------- extent ------------- |
4018                                  */
4019
4020                                 /* subtract range b */
4021                                 if (key.offset + datal > off + len)
4022                                         datal = off + len - key.offset;
4023
4024                                 /* subtract range a */
4025                                 if (off > key.offset) {
4026                                         datao += off - key.offset;
4027                                         datal -= off - key.offset;
4028                                 }
4029
4030                                 ret = btrfs_drop_extents(trans, root, inode,
4031                                                          drop_start,
4032                                                          new_key.offset + datal,
4033                                                          1);
4034                                 if (ret) {
4035                                         if (ret != -EOPNOTSUPP)
4036                                                 btrfs_abort_transaction(trans,
4037                                                                         ret);
4038                                         btrfs_end_transaction(trans);
4039                                         goto out;
4040                                 }
4041
4042                                 ret = btrfs_insert_empty_item(trans, root, path,
4043                                                               &new_key, size);
4044                                 if (ret) {
4045                                         btrfs_abort_transaction(trans, ret);
4046                                         btrfs_end_transaction(trans);
4047                                         goto out;
4048                                 }
4049
4050                                 leaf = path->nodes[0];
4051                                 slot = path->slots[0];
4052                                 write_extent_buffer(leaf, buf,
4053                                             btrfs_item_ptr_offset(leaf, slot),
4054                                             size);
4055
4056                                 extent = btrfs_item_ptr(leaf, slot,
4057                                                 struct btrfs_file_extent_item);
4058
4059                                 /* disko == 0 means it's a hole */
4060                                 if (!disko)
4061                                         datao = 0;
4062
4063                                 btrfs_set_file_extent_offset(leaf, extent,
4064                                                              datao);
4065                                 btrfs_set_file_extent_num_bytes(leaf, extent,
4066                                                                 datal);
4067
4068                                 if (disko) {
4069                                         inode_add_bytes(inode, datal);
4070                                         ret = btrfs_inc_extent_ref(trans,
4071                                                         root,
4072                                                         disko, diskl, 0,
4073                                                         root->root_key.objectid,
4074                                                         btrfs_ino(BTRFS_I(inode)),
4075                                                         new_key.offset - datao);
4076                                         if (ret) {
4077                                                 btrfs_abort_transaction(trans,
4078                                                                         ret);
4079                                                 btrfs_end_transaction(trans);
4080                                                 goto out;
4081
4082                                         }
4083                                 }
4084                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
4085                                 u64 skip = 0;
4086                                 u64 trim = 0;
4087
4088                                 if (off > key.offset) {
4089                                         skip = off - key.offset;
4090                                         new_key.offset += skip;
4091                                 }
4092
4093                                 if (key.offset + datal > off + len)
4094                                         trim = key.offset + datal - (off + len);
4095
4096                                 if (comp && (skip || trim)) {
4097                                         ret = -EINVAL;
4098                                         btrfs_end_transaction(trans);
4099                                         goto out;
4100                                 }
4101                                 size -= skip + trim;
4102                                 datal -= skip + trim;
4103
4104                                 ret = clone_copy_inline_extent(inode,
4105                                                                trans, path,
4106                                                                &new_key,
4107                                                                drop_start,
4108                                                                datal,
4109                                                                skip, size, buf);
4110                                 if (ret) {
4111                                         if (ret != -EOPNOTSUPP)
4112                                                 btrfs_abort_transaction(trans,
4113                                                                         ret);
4114                                         btrfs_end_transaction(trans);
4115                                         goto out;
4116                                 }
4117                                 leaf = path->nodes[0];
4118                                 slot = path->slots[0];
4119                         }
4120
4121                         /* If we have an implicit hole (NO_HOLES feature). */
4122                         if (drop_start < new_key.offset)
4123                                 clone_update_extent_map(BTRFS_I(inode), trans,
4124                                                 NULL, drop_start,
4125                                                 new_key.offset - drop_start);
4126
4127                         clone_update_extent_map(BTRFS_I(inode), trans,
4128                                         path, 0, 0);
4129
4130                         btrfs_mark_buffer_dirty(leaf);
4131                         btrfs_release_path(path);
4132
4133                         last_dest_end = ALIGN(new_key.offset + datal,
4134                                               fs_info->sectorsize);
4135                         ret = clone_finish_inode_update(trans, inode,
4136                                                         last_dest_end,
4137                                                         destoff, olen,
4138                                                         no_time_update);
4139                         if (ret)
4140                                 goto out;
4141                         if (new_key.offset + datal >= destoff + len)
4142                                 break;
4143                 }
4144                 btrfs_release_path(path);
4145                 key.offset = next_key_min_offset;
4146
4147                 if (fatal_signal_pending(current)) {
4148                         ret = -EINTR;
4149                         goto out;
4150                 }
4151         }
4152         ret = 0;
4153
4154         if (last_dest_end < destoff + len) {
4155                 /*
4156                  * We have an implicit hole (NO_HOLES feature is enabled) that
4157                  * fully or partially overlaps our cloning range at its end.
4158                  */
4159                 btrfs_release_path(path);
4160
4161                 /*
4162                  * 1 - remove extent(s)
4163                  * 1 - inode update
4164                  */
4165                 trans = btrfs_start_transaction(root, 2);
4166                 if (IS_ERR(trans)) {
4167                         ret = PTR_ERR(trans);
4168                         goto out;
4169                 }
4170                 ret = btrfs_drop_extents(trans, root, inode,
4171                                          last_dest_end, destoff + len, 1);
4172                 if (ret) {
4173                         if (ret != -EOPNOTSUPP)
4174                                 btrfs_abort_transaction(trans, ret);
4175                         btrfs_end_transaction(trans);
4176                         goto out;
4177                 }
4178                 clone_update_extent_map(BTRFS_I(inode), trans, NULL,
4179                                 last_dest_end,
4180                                 destoff + len - last_dest_end);
4181                 ret = clone_finish_inode_update(trans, inode, destoff + len,
4182                                                 destoff, olen, no_time_update);
4183         }
4184
4185 out:
4186         btrfs_free_path(path);
4187         kvfree(buf);
4188         return ret;
4189 }
4190
4191 static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
4192                                         u64 off, u64 olen, u64 destoff)
4193 {
4194         struct inode *inode = file_inode(file);
4195         struct inode *src = file_inode(file_src);
4196         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4197         struct btrfs_root *root = BTRFS_I(inode)->root;
4198         int ret;
4199         u64 len = olen;
4200         u64 bs = fs_info->sb->s_blocksize;
4201         int same_inode = src == inode;
4202
4203         /*
4204          * TODO:
4205          * - split compressed inline extents.  annoying: we need to
4206          *   decompress into destination's address_space (the file offset
4207          *   may change, so source mapping won't do), then recompress (or
4208          *   otherwise reinsert) a subrange.
4209          *
4210          * - split destination inode's inline extents.  The inline extents can
4211          *   be either compressed or non-compressed.
4212          */
4213
4214         if (btrfs_root_readonly(root))
4215                 return -EROFS;
4216
4217         if (file_src->f_path.mnt != file->f_path.mnt ||
4218             src->i_sb != inode->i_sb)
4219                 return -EXDEV;
4220
4221         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
4222                 return -EISDIR;
4223
4224         if (!same_inode) {
4225                 btrfs_double_inode_lock(src, inode);
4226         } else {
4227                 inode_lock(src);
4228         }
4229
4230         /* don't make the dst file partly checksummed */
4231         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
4232             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
4233                 ret = -EINVAL;
4234                 goto out_unlock;
4235         }
4236
4237         /* determine range to clone */
4238         ret = -EINVAL;
4239         if (off + len > src->i_size || off + len < off)
4240                 goto out_unlock;
4241         if (len == 0)
4242                 olen = len = src->i_size - off;
4243         /* if we extend to eof, continue to block boundary */
4244         if (off + len == src->i_size)
4245                 len = ALIGN(src->i_size, bs) - off;
4246
4247         if (len == 0) {
4248                 ret = 0;
4249                 goto out_unlock;
4250         }
4251
4252         /* verify the end result is block aligned */
4253         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
4254             !IS_ALIGNED(destoff, bs))
4255                 goto out_unlock;
4256
4257         /* verify if ranges are overlapped within the same file */
4258         if (same_inode) {
4259                 if (destoff + len > off && destoff < off + len)
4260                         goto out_unlock;
4261         }
4262
4263         if (destoff > inode->i_size) {
4264                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
4265                 if (ret)
4266                         goto out_unlock;
4267         }
4268
4269         /*
4270          * Lock the target range too. Right after we replace the file extent
4271          * items in the fs tree (which now point to the cloned data), we might
4272          * have a worker replace them with extent items relative to a write
4273          * operation that was issued before this clone operation (i.e. confront
4274          * with inode.c:btrfs_finish_ordered_io).
4275          */
4276         if (same_inode) {
4277                 u64 lock_start = min_t(u64, off, destoff);
4278                 u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
4279
4280                 ret = lock_extent_range(src, lock_start, lock_len, true);
4281         } else {
4282                 ret = btrfs_double_extent_lock(src, off, inode, destoff, len,
4283                                                true);
4284         }
4285         ASSERT(ret == 0);
4286         if (WARN_ON(ret)) {
4287                 /* ranges in the io trees already unlocked */
4288                 goto out_unlock;
4289         }
4290
4291         ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
4292
4293         if (same_inode) {
4294                 u64 lock_start = min_t(u64, off, destoff);
4295                 u64 lock_end = max_t(u64, off, destoff) + len - 1;
4296
4297                 unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
4298         } else {
4299                 btrfs_double_extent_unlock(src, off, inode, destoff, len);
4300         }
4301         /*
4302          * Truncate page cache pages so that future reads will see the cloned
4303          * data immediately and not the previous data.
4304          */
4305         truncate_inode_pages_range(&inode->i_data,
4306                                 round_down(destoff, PAGE_SIZE),
4307                                 round_up(destoff + len, PAGE_SIZE) - 1);
4308 out_unlock:
4309         if (!same_inode)
4310                 btrfs_double_inode_unlock(src, inode);
4311         else
4312                 inode_unlock(src);
4313         return ret;
4314 }
4315
4316 int btrfs_clone_file_range(struct file *src_file, loff_t off,
4317                 struct file *dst_file, loff_t destoff, u64 len)
4318 {
4319         return btrfs_clone_files(dst_file, src_file, off, len, destoff);
4320 }
4321
4322 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
4323 {
4324         struct inode *inode = file_inode(file);
4325         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4326         struct btrfs_root *root = BTRFS_I(inode)->root;
4327         struct btrfs_root *new_root;
4328         struct btrfs_dir_item *di;
4329         struct btrfs_trans_handle *trans;
4330         struct btrfs_path *path;
4331         struct btrfs_key location;
4332         struct btrfs_disk_key disk_key;
4333         u64 objectid = 0;
4334         u64 dir_id;
4335         int ret;
4336
4337         if (!capable(CAP_SYS_ADMIN))
4338                 return -EPERM;
4339
4340         ret = mnt_want_write_file(file);
4341         if (ret)
4342                 return ret;
4343
4344         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
4345                 ret = -EFAULT;
4346                 goto out;
4347         }
4348
4349         if (!objectid)
4350                 objectid = BTRFS_FS_TREE_OBJECTID;
4351
4352         location.objectid = objectid;
4353         location.type = BTRFS_ROOT_ITEM_KEY;
4354         location.offset = (u64)-1;
4355
4356         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
4357         if (IS_ERR(new_root)) {
4358                 ret = PTR_ERR(new_root);
4359                 goto out;
4360         }
4361         if (!is_fstree(new_root->objectid)) {
4362                 ret = -ENOENT;
4363                 goto out;
4364         }
4365
4366         path = btrfs_alloc_path();
4367         if (!path) {
4368                 ret = -ENOMEM;
4369                 goto out;
4370         }
4371         path->leave_spinning = 1;
4372
4373         trans = btrfs_start_transaction(root, 1);
4374         if (IS_ERR(trans)) {
4375                 btrfs_free_path(path);
4376                 ret = PTR_ERR(trans);
4377                 goto out;
4378         }
4379
4380         dir_id = btrfs_super_root_dir(fs_info->super_copy);
4381         di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
4382                                    dir_id, "default", 7, 1);
4383         if (IS_ERR_OR_NULL(di)) {
4384                 btrfs_free_path(path);
4385                 btrfs_end_transaction(trans);
4386                 btrfs_err(fs_info,
4387                           "Umm, you don't have the default diritem, this isn't going to work");
4388                 ret = -ENOENT;
4389                 goto out;
4390         }
4391
4392         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
4393         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
4394         btrfs_mark_buffer_dirty(path->nodes[0]);
4395         btrfs_free_path(path);
4396
4397         btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
4398         btrfs_end_transaction(trans);
4399 out:
4400         mnt_drop_write_file(file);
4401         return ret;
4402 }
4403
4404 static void get_block_group_info(struct list_head *groups_list,
4405                                  struct btrfs_ioctl_space_info *space)
4406 {
4407         struct btrfs_block_group_cache *block_group;
4408
4409         space->total_bytes = 0;
4410         space->used_bytes = 0;
4411         space->flags = 0;
4412         list_for_each_entry(block_group, groups_list, list) {
4413                 space->flags = block_group->flags;
4414                 space->total_bytes += block_group->key.offset;
4415                 space->used_bytes +=
4416                         btrfs_block_group_used(&block_group->item);
4417         }
4418 }
4419
4420 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
4421                                    void __user *arg)
4422 {
4423         struct btrfs_ioctl_space_args space_args;
4424         struct btrfs_ioctl_space_info space;
4425         struct btrfs_ioctl_space_info *dest;
4426         struct btrfs_ioctl_space_info *dest_orig;
4427         struct btrfs_ioctl_space_info __user *user_dest;
4428         struct btrfs_space_info *info;
4429         static const u64 types[] = {
4430                 BTRFS_BLOCK_GROUP_DATA,
4431                 BTRFS_BLOCK_GROUP_SYSTEM,
4432                 BTRFS_BLOCK_GROUP_METADATA,
4433                 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
4434         };
4435         int num_types = 4;
4436         int alloc_size;
4437         int ret = 0;
4438         u64 slot_count = 0;
4439         int i, c;
4440
4441         if (copy_from_user(&space_args,
4442                            (struct btrfs_ioctl_space_args __user *)arg,
4443                            sizeof(space_args)))
4444                 return -EFAULT;
4445
4446         for (i = 0; i < num_types; i++) {
4447                 struct btrfs_space_info *tmp;
4448
4449                 info = NULL;
4450                 rcu_read_lock();
4451                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4452                                         list) {
4453                         if (tmp->flags == types[i]) {
4454                                 info = tmp;
4455                                 break;
4456                         }
4457                 }
4458                 rcu_read_unlock();
4459
4460                 if (!info)
4461                         continue;
4462
4463                 down_read(&info->groups_sem);
4464                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4465                         if (!list_empty(&info->block_groups[c]))
4466                                 slot_count++;
4467                 }
4468                 up_read(&info->groups_sem);
4469         }
4470
4471         /*
4472          * Global block reserve, exported as a space_info
4473          */
4474         slot_count++;
4475
4476         /* space_slots == 0 means they are asking for a count */
4477         if (space_args.space_slots == 0) {
4478                 space_args.total_spaces = slot_count;
4479                 goto out;
4480         }
4481
4482         slot_count = min_t(u64, space_args.space_slots, slot_count);
4483
4484         alloc_size = sizeof(*dest) * slot_count;
4485
4486         /* we generally have at most 6 or so space infos, one for each raid
4487          * level.  So, a whole page should be more than enough for everyone
4488          */
4489         if (alloc_size > PAGE_SIZE)
4490                 return -ENOMEM;
4491
4492         space_args.total_spaces = 0;
4493         dest = kmalloc(alloc_size, GFP_KERNEL);
4494         if (!dest)
4495                 return -ENOMEM;
4496         dest_orig = dest;
4497
4498         /* now we have a buffer to copy into */
4499         for (i = 0; i < num_types; i++) {
4500                 struct btrfs_space_info *tmp;
4501
4502                 if (!slot_count)
4503                         break;
4504
4505                 info = NULL;
4506                 rcu_read_lock();
4507                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4508                                         list) {
4509                         if (tmp->flags == types[i]) {
4510                                 info = tmp;
4511                                 break;
4512                         }
4513                 }
4514                 rcu_read_unlock();
4515
4516                 if (!info)
4517                         continue;
4518                 down_read(&info->groups_sem);
4519                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4520                         if (!list_empty(&info->block_groups[c])) {
4521                                 get_block_group_info(&info->block_groups[c],
4522                                                      &space);
4523                                 memcpy(dest, &space, sizeof(space));
4524                                 dest++;
4525                                 space_args.total_spaces++;
4526                                 slot_count--;
4527                         }
4528                         if (!slot_count)
4529                                 break;
4530                 }
4531                 up_read(&info->groups_sem);
4532         }
4533
4534         /*
4535          * Add global block reserve
4536          */
4537         if (slot_count) {
4538                 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
4539
4540                 spin_lock(&block_rsv->lock);
4541                 space.total_bytes = block_rsv->size;
4542                 space.used_bytes = block_rsv->size - block_rsv->reserved;
4543                 spin_unlock(&block_rsv->lock);
4544                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4545                 memcpy(dest, &space, sizeof(space));
4546                 space_args.total_spaces++;
4547         }
4548
4549         user_dest = (struct btrfs_ioctl_space_info __user *)
4550                 (arg + sizeof(struct btrfs_ioctl_space_args));
4551
4552         if (copy_to_user(user_dest, dest_orig, alloc_size))
4553                 ret = -EFAULT;
4554
4555         kfree(dest_orig);
4556 out:
4557         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4558                 ret = -EFAULT;
4559
4560         return ret;
4561 }
4562
4563 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4564                                             void __user *argp)
4565 {
4566         struct btrfs_trans_handle *trans;
4567         u64 transid;
4568         int ret;
4569
4570         trans = btrfs_attach_transaction_barrier(root);
4571         if (IS_ERR(trans)) {
4572                 if (PTR_ERR(trans) != -ENOENT)
4573                         return PTR_ERR(trans);
4574
4575                 /* No running transaction, don't bother */
4576                 transid = root->fs_info->last_trans_committed;
4577                 goto out;
4578         }
4579         transid = trans->transid;
4580         ret = btrfs_commit_transaction_async(trans, 0);
4581         if (ret) {
4582                 btrfs_end_transaction(trans);
4583                 return ret;
4584         }
4585 out:
4586         if (argp)
4587                 if (copy_to_user(argp, &transid, sizeof(transid)))
4588                         return -EFAULT;
4589         return 0;
4590 }
4591
4592 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
4593                                            void __user *argp)
4594 {
4595         u64 transid;
4596
4597         if (argp) {
4598                 if (copy_from_user(&transid, argp, sizeof(transid)))
4599                         return -EFAULT;
4600         } else {
4601                 transid = 0;  /* current trans */
4602         }
4603         return btrfs_wait_for_commit(fs_info, transid);
4604 }
4605
4606 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4607 {
4608         struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
4609         struct btrfs_ioctl_scrub_args *sa;
4610         int ret;
4611
4612         if (!capable(CAP_SYS_ADMIN))
4613                 return -EPERM;
4614
4615         sa = memdup_user(arg, sizeof(*sa));
4616         if (IS_ERR(sa))
4617                 return PTR_ERR(sa);
4618
4619         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4620                 ret = mnt_want_write_file(file);
4621                 if (ret)
4622                         goto out;
4623         }
4624
4625         ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
4626                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4627                               0);
4628
4629         if (copy_to_user(arg, sa, sizeof(*sa)))
4630                 ret = -EFAULT;
4631
4632         if (!(sa->flags & BTRFS_SCRUB_READONLY))
4633                 mnt_drop_write_file(file);
4634 out:
4635         kfree(sa);
4636         return ret;
4637 }
4638
4639 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
4640 {
4641         if (!capable(CAP_SYS_ADMIN))
4642                 return -EPERM;
4643
4644         return btrfs_scrub_cancel(fs_info);
4645 }
4646
4647 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
4648                                        void __user *arg)
4649 {
4650         struct btrfs_ioctl_scrub_args *sa;
4651         int ret;
4652
4653         if (!capable(CAP_SYS_ADMIN))
4654                 return -EPERM;
4655
4656         sa = memdup_user(arg, sizeof(*sa));
4657         if (IS_ERR(sa))
4658                 return PTR_ERR(sa);
4659
4660         ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
4661
4662         if (copy_to_user(arg, sa, sizeof(*sa)))
4663                 ret = -EFAULT;
4664
4665         kfree(sa);
4666         return ret;
4667 }
4668
4669 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
4670                                       void __user *arg)
4671 {
4672         struct btrfs_ioctl_get_dev_stats *sa;
4673         int ret;
4674
4675         sa = memdup_user(arg, sizeof(*sa));
4676         if (IS_ERR(sa))
4677                 return PTR_ERR(sa);
4678
4679         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4680                 kfree(sa);
4681                 return -EPERM;
4682         }
4683
4684         ret = btrfs_get_dev_stats(fs_info, sa);
4685
4686         if (copy_to_user(arg, sa, sizeof(*sa)))
4687                 ret = -EFAULT;
4688
4689         kfree(sa);
4690         return ret;
4691 }
4692
4693 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
4694                                     void __user *arg)
4695 {
4696         struct btrfs_ioctl_dev_replace_args *p;
4697         int ret;
4698
4699         if (!capable(CAP_SYS_ADMIN))
4700                 return -EPERM;
4701
4702         p = memdup_user(arg, sizeof(*p));
4703         if (IS_ERR(p))
4704                 return PTR_ERR(p);
4705
4706         switch (p->cmd) {
4707         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4708                 if (sb_rdonly(fs_info->sb)) {
4709                         ret = -EROFS;
4710                         goto out;
4711                 }
4712                 if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4713                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4714                 } else {
4715                         ret = btrfs_dev_replace_by_ioctl(fs_info, p);
4716                         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4717                 }
4718                 break;
4719         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4720                 btrfs_dev_replace_status(fs_info, p);
4721                 ret = 0;
4722                 break;
4723         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4724                 p->result = btrfs_dev_replace_cancel(fs_info);
4725                 ret = 0;
4726                 break;
4727         default:
4728                 ret = -EINVAL;
4729                 break;
4730         }
4731
4732         if (copy_to_user(arg, p, sizeof(*p)))
4733                 ret = -EFAULT;
4734 out:
4735         kfree(p);
4736         return ret;
4737 }
4738
4739 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4740 {
4741         int ret = 0;
4742         int i;
4743         u64 rel_ptr;
4744         int size;
4745         struct btrfs_ioctl_ino_path_args *ipa = NULL;
4746         struct inode_fs_paths *ipath = NULL;
4747         struct btrfs_path *path;
4748
4749         if (!capable(CAP_DAC_READ_SEARCH))
4750                 return -EPERM;
4751
4752         path = btrfs_alloc_path();
4753         if (!path) {
4754                 ret = -ENOMEM;
4755                 goto out;
4756         }
4757
4758         ipa = memdup_user(arg, sizeof(*ipa));
4759         if (IS_ERR(ipa)) {
4760                 ret = PTR_ERR(ipa);
4761                 ipa = NULL;
4762                 goto out;
4763         }
4764
4765         size = min_t(u32, ipa->size, 4096);
4766         ipath = init_ipath(size, root, path);
4767         if (IS_ERR(ipath)) {
4768                 ret = PTR_ERR(ipath);
4769                 ipath = NULL;
4770                 goto out;
4771         }
4772
4773         ret = paths_from_inode(ipa->inum, ipath);
4774         if (ret < 0)
4775                 goto out;
4776
4777         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4778                 rel_ptr = ipath->fspath->val[i] -
4779                           (u64)(unsigned long)ipath->fspath->val;
4780                 ipath->fspath->val[i] = rel_ptr;
4781         }
4782
4783         ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
4784                            ipath->fspath, size);
4785         if (ret) {
4786                 ret = -EFAULT;
4787                 goto out;
4788         }
4789
4790 out:
4791         btrfs_free_path(path);
4792         free_ipath(ipath);
4793         kfree(ipa);
4794
4795         return ret;
4796 }
4797
4798 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4799 {
4800         struct btrfs_data_container *inodes = ctx;
4801         const size_t c = 3 * sizeof(u64);
4802
4803         if (inodes->bytes_left >= c) {
4804                 inodes->bytes_left -= c;
4805                 inodes->val[inodes->elem_cnt] = inum;
4806                 inodes->val[inodes->elem_cnt + 1] = offset;
4807                 inodes->val[inodes->elem_cnt + 2] = root;
4808                 inodes->elem_cnt += 3;
4809         } else {
4810                 inodes->bytes_missing += c - inodes->bytes_left;
4811                 inodes->bytes_left = 0;
4812                 inodes->elem_missed += 3;
4813         }
4814
4815         return 0;
4816 }
4817
4818 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
4819                                         void __user *arg, int version)
4820 {
4821         int ret = 0;
4822         int size;
4823         struct btrfs_ioctl_logical_ino_args *loi;
4824         struct btrfs_data_container *inodes = NULL;
4825         struct btrfs_path *path = NULL;
4826         bool ignore_offset;
4827
4828         if (!capable(CAP_SYS_ADMIN))
4829                 return -EPERM;
4830
4831         loi = memdup_user(arg, sizeof(*loi));
4832         if (IS_ERR(loi))
4833                 return PTR_ERR(loi);
4834
4835         if (version == 1) {
4836                 ignore_offset = false;
4837                 size = min_t(u32, loi->size, SZ_64K);
4838         } else {
4839                 /* All reserved bits must be 0 for now */
4840                 if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
4841                         ret = -EINVAL;
4842                         goto out_loi;
4843                 }
4844                 /* Only accept flags we have defined so far */
4845                 if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
4846                         ret = -EINVAL;
4847                         goto out_loi;
4848                 }
4849                 ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
4850                 size = min_t(u32, loi->size, SZ_16M);
4851         }
4852
4853         path = btrfs_alloc_path();
4854         if (!path) {
4855                 ret = -ENOMEM;
4856                 goto out;
4857         }
4858
4859         inodes = init_data_container(size);
4860         if (IS_ERR(inodes)) {
4861                 ret = PTR_ERR(inodes);
4862                 inodes = NULL;
4863                 goto out;
4864         }
4865
4866         ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
4867                                           build_ino_list, inodes, ignore_offset);
4868         if (ret == -EINVAL)
4869                 ret = -ENOENT;
4870         if (ret < 0)
4871                 goto out;
4872
4873         ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
4874                            size);
4875         if (ret)
4876                 ret = -EFAULT;
4877
4878 out:
4879         btrfs_free_path(path);
4880         kvfree(inodes);
4881 out_loi:
4882         kfree(loi);
4883
4884         return ret;
4885 }
4886
4887 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
4888                                struct btrfs_ioctl_balance_args *bargs)
4889 {
4890         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4891
4892         bargs->flags = bctl->flags;
4893
4894         if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags))
4895                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4896         if (atomic_read(&fs_info->balance_pause_req))
4897                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4898         if (atomic_read(&fs_info->balance_cancel_req))
4899                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4900
4901         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4902         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4903         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4904
4905         spin_lock(&fs_info->balance_lock);
4906         memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4907         spin_unlock(&fs_info->balance_lock);
4908 }
4909
4910 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4911 {
4912         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4913         struct btrfs_fs_info *fs_info = root->fs_info;
4914         struct btrfs_ioctl_balance_args *bargs;
4915         struct btrfs_balance_control *bctl;
4916         bool need_unlock; /* for mut. excl. ops lock */
4917         int ret;
4918
4919         if (!capable(CAP_SYS_ADMIN))
4920                 return -EPERM;
4921
4922         ret = mnt_want_write_file(file);
4923         if (ret)
4924                 return ret;
4925
4926 again:
4927         if (!test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4928                 mutex_lock(&fs_info->balance_mutex);
4929                 need_unlock = true;
4930                 goto locked;
4931         }
4932
4933         /*
4934          * mut. excl. ops lock is locked.  Three possibilities:
4935          *   (1) some other op is running
4936          *   (2) balance is running
4937          *   (3) balance is paused -- special case (think resume)
4938          */
4939         mutex_lock(&fs_info->balance_mutex);
4940         if (fs_info->balance_ctl) {
4941                 /* this is either (2) or (3) */
4942                 if (!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4943                         mutex_unlock(&fs_info->balance_mutex);
4944                         /*
4945                          * Lock released to allow other waiters to continue,
4946                          * we'll reexamine the status again.
4947                          */
4948                         mutex_lock(&fs_info->balance_mutex);
4949
4950                         if (fs_info->balance_ctl &&
4951                             !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4952                                 /* this is (3) */
4953                                 need_unlock = false;
4954                                 goto locked;
4955                         }
4956
4957                         mutex_unlock(&fs_info->balance_mutex);
4958                         goto again;
4959                 } else {
4960                         /* this is (2) */
4961                         mutex_unlock(&fs_info->balance_mutex);
4962                         ret = -EINPROGRESS;
4963                         goto out;
4964                 }
4965         } else {
4966                 /* this is (1) */
4967                 mutex_unlock(&fs_info->balance_mutex);
4968                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4969                 goto out;
4970         }
4971
4972 locked:
4973         BUG_ON(!test_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));
4974
4975         if (arg) {
4976                 bargs = memdup_user(arg, sizeof(*bargs));
4977                 if (IS_ERR(bargs)) {
4978                         ret = PTR_ERR(bargs);
4979                         goto out_unlock;
4980                 }
4981
4982                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
4983                         if (!fs_info->balance_ctl) {
4984                                 ret = -ENOTCONN;
4985                                 goto out_bargs;
4986                         }
4987
4988                         bctl = fs_info->balance_ctl;
4989                         spin_lock(&fs_info->balance_lock);
4990                         bctl->flags |= BTRFS_BALANCE_RESUME;
4991                         spin_unlock(&fs_info->balance_lock);
4992
4993                         goto do_balance;
4994                 }
4995         } else {
4996                 bargs = NULL;
4997         }
4998
4999         if (fs_info->balance_ctl) {
5000                 ret = -EINPROGRESS;
5001                 goto out_bargs;
5002         }
5003
5004         bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
5005         if (!bctl) {
5006                 ret = -ENOMEM;
5007                 goto out_bargs;
5008         }
5009
5010         if (arg) {
5011                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
5012                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
5013                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
5014
5015                 bctl->flags = bargs->flags;
5016         } else {
5017                 /* balance everything - no filters */
5018                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
5019         }
5020
5021         if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
5022                 ret = -EINVAL;
5023                 goto out_bctl;
5024         }
5025
5026 do_balance:
5027         /*
5028          * Ownership of bctl and filesystem flag BTRFS_FS_EXCL_OP goes to
5029          * btrfs_balance.  bctl is freed in reset_balance_state, or, if
5030          * restriper was paused all the way until unmount, in free_fs_info.
5031          * The flag should be cleared after reset_balance_state.
5032          */
5033         need_unlock = false;
5034
5035         ret = btrfs_balance(fs_info, bctl, bargs);
5036         bctl = NULL;
5037
5038         if (arg) {
5039                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
5040                         ret = -EFAULT;
5041         }
5042
5043 out_bctl:
5044         kfree(bctl);
5045 out_bargs:
5046         kfree(bargs);
5047 out_unlock:
5048         mutex_unlock(&fs_info->balance_mutex);
5049         if (need_unlock)
5050                 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
5051 out:
5052         mnt_drop_write_file(file);
5053         return ret;
5054 }
5055
5056 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
5057 {
5058         if (!capable(CAP_SYS_ADMIN))
5059                 return -EPERM;
5060
5061         switch (cmd) {
5062         case BTRFS_BALANCE_CTL_PAUSE:
5063                 return btrfs_pause_balance(fs_info);
5064         case BTRFS_BALANCE_CTL_CANCEL:
5065                 return btrfs_cancel_balance(fs_info);
5066         }
5067
5068         return -EINVAL;
5069 }
5070
5071 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
5072                                          void __user *arg)
5073 {
5074         struct btrfs_ioctl_balance_args *bargs;
5075         int ret = 0;
5076
5077         if (!capable(CAP_SYS_ADMIN))
5078                 return -EPERM;
5079
5080         mutex_lock(&fs_info->balance_mutex);
5081         if (!fs_info->balance_ctl) {
5082                 ret = -ENOTCONN;
5083                 goto out;
5084         }
5085
5086         bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
5087         if (!bargs) {
5088                 ret = -ENOMEM;
5089                 goto out;
5090         }
5091
5092         btrfs_update_ioctl_balance_args(fs_info, bargs);
5093
5094         if (copy_to_user(arg, bargs, sizeof(*bargs)))
5095                 ret = -EFAULT;
5096
5097         kfree(bargs);
5098 out:
5099         mutex_unlock(&fs_info->balance_mutex);
5100         return ret;
5101 }
5102
5103 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
5104 {
5105         struct inode *inode = file_inode(file);
5106         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5107         struct btrfs_ioctl_quota_ctl_args *sa;
5108         int ret;
5109
5110         if (!capable(CAP_SYS_ADMIN))
5111                 return -EPERM;
5112
5113         ret = mnt_want_write_file(file);
5114         if (ret)
5115                 return ret;
5116
5117         sa = memdup_user(arg, sizeof(*sa));
5118         if (IS_ERR(sa)) {
5119                 ret = PTR_ERR(sa);
5120                 goto drop_write;
5121         }
5122
5123         down_write(&fs_info->subvol_sem);
5124
5125         switch (sa->cmd) {
5126         case BTRFS_QUOTA_CTL_ENABLE:
5127                 ret = btrfs_quota_enable(fs_info);
5128                 break;
5129         case BTRFS_QUOTA_CTL_DISABLE:
5130                 ret = btrfs_quota_disable(fs_info);
5131                 break;
5132         default:
5133                 ret = -EINVAL;
5134                 break;
5135         }
5136
5137         kfree(sa);
5138         up_write(&fs_info->subvol_sem);
5139 drop_write:
5140         mnt_drop_write_file(file);
5141         return ret;
5142 }
5143
5144 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
5145 {
5146         struct inode *inode = file_inode(file);
5147         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5148         struct btrfs_root *root = BTRFS_I(inode)->root;
5149         struct btrfs_ioctl_qgroup_assign_args *sa;
5150         struct btrfs_trans_handle *trans;
5151         int ret;
5152         int err;
5153
5154         if (!capable(CAP_SYS_ADMIN))
5155                 return -EPERM;
5156
5157         ret = mnt_want_write_file(file);
5158         if (ret)
5159                 return ret;
5160
5161         sa = memdup_user(arg, sizeof(*sa));
5162         if (IS_ERR(sa)) {
5163                 ret = PTR_ERR(sa);
5164                 goto drop_write;
5165         }
5166
5167         trans = btrfs_join_transaction(root);
5168         if (IS_ERR(trans)) {
5169                 ret = PTR_ERR(trans);
5170                 goto out;
5171         }
5172
5173         if (sa->assign) {
5174                 ret = btrfs_add_qgroup_relation(trans, sa->src, sa->dst);
5175         } else {
5176                 ret = btrfs_del_qgroup_relation(trans, sa->src, sa->dst);
5177         }
5178
5179         /* update qgroup status and info */
5180         err = btrfs_run_qgroups(trans);
5181         if (err < 0)
5182                 btrfs_handle_fs_error(fs_info, err,
5183                                       "failed to update qgroup status and info");
5184         err = btrfs_end_transaction(trans);
5185         if (err && !ret)
5186                 ret = err;
5187
5188 out:
5189         kfree(sa);
5190 drop_write:
5191         mnt_drop_write_file(file);
5192         return ret;
5193 }
5194
5195 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
5196 {
5197         struct inode *inode = file_inode(file);
5198         struct btrfs_root *root = BTRFS_I(inode)->root;
5199         struct btrfs_ioctl_qgroup_create_args *sa;
5200         struct btrfs_trans_handle *trans;
5201         int ret;
5202         int err;
5203
5204         if (!capable(CAP_SYS_ADMIN))
5205                 return -EPERM;
5206
5207         ret = mnt_want_write_file(file);
5208         if (ret)
5209                 return ret;
5210
5211         sa = memdup_user(arg, sizeof(*sa));
5212         if (IS_ERR(sa)) {
5213                 ret = PTR_ERR(sa);
5214                 goto drop_write;
5215         }
5216
5217         if (!sa->qgroupid) {
5218                 ret = -EINVAL;
5219                 goto out;
5220         }
5221
5222         trans = btrfs_join_transaction(root);
5223         if (IS_ERR(trans)) {
5224                 ret = PTR_ERR(trans);
5225                 goto out;
5226         }
5227
5228         if (sa->create) {
5229                 ret = btrfs_create_qgroup(trans, sa->qgroupid);
5230         } else {
5231                 ret = btrfs_remove_qgroup(trans, sa->qgroupid);
5232         }
5233
5234         err = btrfs_end_transaction(trans);
5235         if (err && !ret)
5236                 ret = err;
5237
5238 out:
5239         kfree(sa);
5240 drop_write:
5241         mnt_drop_write_file(file);
5242         return ret;
5243 }
5244
5245 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
5246 {
5247         struct inode *inode = file_inode(file);
5248         struct btrfs_root *root = BTRFS_I(inode)->root;
5249         struct btrfs_ioctl_qgroup_limit_args *sa;
5250         struct btrfs_trans_handle *trans;
5251         int ret;
5252         int err;
5253         u64 qgroupid;
5254
5255         if (!capable(CAP_SYS_ADMIN))
5256                 return -EPERM;
5257
5258         ret = mnt_want_write_file(file);
5259         if (ret)
5260                 return ret;
5261
5262         sa = memdup_user(arg, sizeof(*sa));
5263         if (IS_ERR(sa)) {
5264                 ret = PTR_ERR(sa);
5265                 goto drop_write;
5266         }
5267
5268         trans = btrfs_join_transaction(root);
5269         if (IS_ERR(trans)) {
5270                 ret = PTR_ERR(trans);
5271                 goto out;
5272         }
5273
5274         qgroupid = sa->qgroupid;
5275         if (!qgroupid) {
5276                 /* take the current subvol as qgroup */
5277                 qgroupid = root->root_key.objectid;
5278         }
5279
5280         ret = btrfs_limit_qgroup(trans, qgroupid, &sa->lim);
5281
5282         err = btrfs_end_transaction(trans);
5283         if (err && !ret)
5284                 ret = err;
5285
5286 out:
5287         kfree(sa);
5288 drop_write:
5289         mnt_drop_write_file(file);
5290         return ret;
5291 }
5292
5293 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
5294 {
5295         struct inode *inode = file_inode(file);
5296         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5297         struct btrfs_ioctl_quota_rescan_args *qsa;
5298         int ret;
5299
5300         if (!capable(CAP_SYS_ADMIN))
5301                 return -EPERM;
5302
5303         ret = mnt_want_write_file(file);
5304         if (ret)
5305                 return ret;
5306
5307         qsa = memdup_user(arg, sizeof(*qsa));
5308         if (IS_ERR(qsa)) {
5309                 ret = PTR_ERR(qsa);
5310                 goto drop_write;
5311         }
5312
5313         if (qsa->flags) {
5314                 ret = -EINVAL;
5315                 goto out;
5316         }
5317
5318         ret = btrfs_qgroup_rescan(fs_info);
5319
5320 out:
5321         kfree(qsa);
5322 drop_write:
5323         mnt_drop_write_file(file);
5324         return ret;
5325 }
5326
5327 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
5328 {
5329         struct inode *inode = file_inode(file);
5330         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5331         struct btrfs_ioctl_quota_rescan_args *qsa;
5332         int ret = 0;
5333
5334         if (!capable(CAP_SYS_ADMIN))
5335                 return -EPERM;
5336
5337         qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
5338         if (!qsa)
5339                 return -ENOMEM;
5340
5341         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
5342                 qsa->flags = 1;
5343                 qsa->progress = fs_info->qgroup_rescan_progress.objectid;
5344         }
5345
5346         if (copy_to_user(arg, qsa, sizeof(*qsa)))
5347                 ret = -EFAULT;
5348
5349         kfree(qsa);
5350         return ret;
5351 }
5352
5353 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
5354 {
5355         struct inode *inode = file_inode(file);
5356         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5357
5358         if (!capable(CAP_SYS_ADMIN))
5359                 return -EPERM;
5360
5361         return btrfs_qgroup_wait_for_completion(fs_info, true);
5362 }
5363
5364 static long _btrfs_ioctl_set_received_subvol(struct file *file,
5365                                             struct btrfs_ioctl_received_subvol_args *sa)
5366 {
5367         struct inode *inode = file_inode(file);
5368         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5369         struct btrfs_root *root = BTRFS_I(inode)->root;
5370         struct btrfs_root_item *root_item = &root->root_item;
5371         struct btrfs_trans_handle *trans;
5372         struct timespec64 ct = current_time(inode);
5373         int ret = 0;
5374         int received_uuid_changed;
5375
5376         if (!inode_owner_or_capable(inode))
5377                 return -EPERM;
5378
5379         ret = mnt_want_write_file(file);
5380         if (ret < 0)
5381                 return ret;
5382
5383         down_write(&fs_info->subvol_sem);
5384
5385         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
5386                 ret = -EINVAL;
5387                 goto out;
5388         }
5389
5390         if (btrfs_root_readonly(root)) {
5391                 ret = -EROFS;
5392                 goto out;
5393         }
5394
5395         /*
5396          * 1 - root item
5397          * 2 - uuid items (received uuid + subvol uuid)
5398          */
5399         trans = btrfs_start_transaction(root, 3);
5400         if (IS_ERR(trans)) {
5401                 ret = PTR_ERR(trans);
5402                 trans = NULL;
5403                 goto out;
5404         }
5405
5406         sa->rtransid = trans->transid;
5407         sa->rtime.sec = ct.tv_sec;
5408         sa->rtime.nsec = ct.tv_nsec;
5409
5410         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5411                                        BTRFS_UUID_SIZE);
5412         if (received_uuid_changed &&
5413             !btrfs_is_empty_uuid(root_item->received_uuid)) {
5414                 ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
5415                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5416                                           root->root_key.objectid);
5417                 if (ret && ret != -ENOENT) {
5418                         btrfs_abort_transaction(trans, ret);
5419                         btrfs_end_transaction(trans);
5420                         goto out;
5421                 }
5422         }
5423         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5424         btrfs_set_root_stransid(root_item, sa->stransid);
5425         btrfs_set_root_rtransid(root_item, sa->rtransid);
5426         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5427         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5428         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5429         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5430
5431         ret = btrfs_update_root(trans, fs_info->tree_root,
5432                                 &root->root_key, &root->root_item);
5433         if (ret < 0) {
5434                 btrfs_end_transaction(trans);
5435                 goto out;
5436         }
5437         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5438                 ret = btrfs_uuid_tree_add(trans, sa->uuid,
5439                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5440                                           root->root_key.objectid);
5441                 if (ret < 0 && ret != -EEXIST) {
5442                         btrfs_abort_transaction(trans, ret);
5443                         btrfs_end_transaction(trans);
5444                         goto out;
5445                 }
5446         }
5447         ret = btrfs_commit_transaction(trans);
5448 out:
5449         up_write(&fs_info->subvol_sem);
5450         mnt_drop_write_file(file);
5451         return ret;
5452 }
5453
5454 #ifdef CONFIG_64BIT
5455 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5456                                                 void __user *arg)
5457 {
5458         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5459         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5460         int ret = 0;
5461
5462         args32 = memdup_user(arg, sizeof(*args32));
5463         if (IS_ERR(args32))
5464                 return PTR_ERR(args32);
5465
5466         args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
5467         if (!args64) {
5468                 ret = -ENOMEM;
5469                 goto out;
5470         }
5471
5472         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5473         args64->stransid = args32->stransid;
5474         args64->rtransid = args32->rtransid;
5475         args64->stime.sec = args32->stime.sec;
5476         args64->stime.nsec = args32->stime.nsec;
5477         args64->rtime.sec = args32->rtime.sec;
5478         args64->rtime.nsec = args32->rtime.nsec;
5479         args64->flags = args32->flags;
5480
5481         ret = _btrfs_ioctl_set_received_subvol(file, args64);
5482         if (ret)
5483                 goto out;
5484
5485         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5486         args32->stransid = args64->stransid;
5487         args32->rtransid = args64->rtransid;
5488         args32->stime.sec = args64->stime.sec;
5489         args32->stime.nsec = args64->stime.nsec;
5490         args32->rtime.sec = args64->rtime.sec;
5491         args32->rtime.nsec = args64->rtime.nsec;
5492         args32->flags = args64->flags;
5493
5494         ret = copy_to_user(arg, args32, sizeof(*args32));
5495         if (ret)
5496                 ret = -EFAULT;
5497
5498 out:
5499         kfree(args32);
5500         kfree(args64);
5501         return ret;
5502 }
5503 #endif
5504
5505 static long btrfs_ioctl_set_received_subvol(struct file *file,
5506                                             void __user *arg)
5507 {
5508         struct btrfs_ioctl_received_subvol_args *sa = NULL;
5509         int ret = 0;
5510
5511         sa = memdup_user(arg, sizeof(*sa));
5512         if (IS_ERR(sa))
5513                 return PTR_ERR(sa);
5514
5515         ret = _btrfs_ioctl_set_received_subvol(file, sa);
5516
5517         if (ret)
5518                 goto out;
5519
5520         ret = copy_to_user(arg, sa, sizeof(*sa));
5521         if (ret)
5522                 ret = -EFAULT;
5523
5524 out:
5525         kfree(sa);
5526         return ret;
5527 }
5528
5529 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
5530 {
5531         struct inode *inode = file_inode(file);
5532         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5533         size_t len;
5534         int ret;
5535         char label[BTRFS_LABEL_SIZE];
5536
5537         spin_lock(&fs_info->super_lock);
5538         memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5539         spin_unlock(&fs_info->super_lock);
5540
5541         len = strnlen(label, BTRFS_LABEL_SIZE);
5542
5543         if (len == BTRFS_LABEL_SIZE) {
5544                 btrfs_warn(fs_info,
5545                            "label is too long, return the first %zu bytes",
5546                            --len);
5547         }
5548
5549         ret = copy_to_user(arg, label, len);
5550
5551         return ret ? -EFAULT : 0;
5552 }
5553
5554 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5555 {
5556         struct inode *inode = file_inode(file);
5557         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5558         struct btrfs_root *root = BTRFS_I(inode)->root;
5559         struct btrfs_super_block *super_block = fs_info->super_copy;
5560         struct btrfs_trans_handle *trans;
5561         char label[BTRFS_LABEL_SIZE];
5562         int ret;
5563
5564         if (!capable(CAP_SYS_ADMIN))
5565                 return -EPERM;
5566
5567         if (copy_from_user(label, arg, sizeof(label)))
5568                 return -EFAULT;
5569
5570         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5571                 btrfs_err(fs_info,
5572                           "unable to set label with more than %d bytes",
5573                           BTRFS_LABEL_SIZE - 1);
5574                 return -EINVAL;
5575         }
5576
5577         ret = mnt_want_write_file(file);
5578         if (ret)
5579                 return ret;
5580
5581         trans = btrfs_start_transaction(root, 0);
5582         if (IS_ERR(trans)) {
5583                 ret = PTR_ERR(trans);
5584                 goto out_unlock;
5585         }
5586
5587         spin_lock(&fs_info->super_lock);
5588         strcpy(super_block->label, label);
5589         spin_unlock(&fs_info->super_lock);
5590         ret = btrfs_commit_transaction(trans);
5591
5592 out_unlock:
5593         mnt_drop_write_file(file);
5594         return ret;
5595 }
5596
5597 #define INIT_FEATURE_FLAGS(suffix) \
5598         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5599           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5600           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5601
5602 int btrfs_ioctl_get_supported_features(void __user *arg)
5603 {
5604         static const struct btrfs_ioctl_feature_flags features[3] = {
5605                 INIT_FEATURE_FLAGS(SUPP),
5606                 INIT_FEATURE_FLAGS(SAFE_SET),
5607                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
5608         };
5609
5610         if (copy_to_user(arg, &features, sizeof(features)))
5611                 return -EFAULT;
5612
5613         return 0;
5614 }
5615
5616 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5617 {
5618         struct inode *inode = file_inode(file);
5619         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5620         struct btrfs_super_block *super_block = fs_info->super_copy;
5621         struct btrfs_ioctl_feature_flags features;
5622
5623         features.compat_flags = btrfs_super_compat_flags(super_block);
5624         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5625         features.incompat_flags = btrfs_super_incompat_flags(super_block);
5626
5627         if (copy_to_user(arg, &features, sizeof(features)))
5628                 return -EFAULT;
5629
5630         return 0;
5631 }
5632
5633 static int check_feature_bits(struct btrfs_fs_info *fs_info,
5634                               enum btrfs_feature_set set,
5635                               u64 change_mask, u64 flags, u64 supported_flags,
5636                               u64 safe_set, u64 safe_clear)
5637 {
5638         const char *type = btrfs_feature_set_names[set];
5639         char *names;
5640         u64 disallowed, unsupported;
5641         u64 set_mask = flags & change_mask;
5642         u64 clear_mask = ~flags & change_mask;
5643
5644         unsupported = set_mask & ~supported_flags;
5645         if (unsupported) {
5646                 names = btrfs_printable_features(set, unsupported);
5647                 if (names) {
5648                         btrfs_warn(fs_info,
5649                                    "this kernel does not support the %s feature bit%s",
5650                                    names, strchr(names, ',') ? "s" : "");
5651                         kfree(names);
5652                 } else
5653                         btrfs_warn(fs_info,
5654                                    "this kernel does not support %s bits 0x%llx",
5655                                    type, unsupported);
5656                 return -EOPNOTSUPP;
5657         }
5658
5659         disallowed = set_mask & ~safe_set;
5660         if (disallowed) {
5661                 names = btrfs_printable_features(set, disallowed);
5662                 if (names) {
5663                         btrfs_warn(fs_info,
5664                                    "can't set the %s feature bit%s while mounted",
5665                                    names, strchr(names, ',') ? "s" : "");
5666                         kfree(names);
5667                 } else
5668                         btrfs_warn(fs_info,
5669                                    "can't set %s bits 0x%llx while mounted",
5670                                    type, disallowed);
5671                 return -EPERM;
5672         }
5673
5674         disallowed = clear_mask & ~safe_clear;
5675         if (disallowed) {
5676                 names = btrfs_printable_features(set, disallowed);
5677                 if (names) {
5678                         btrfs_warn(fs_info,
5679                                    "can't clear the %s feature bit%s while mounted",
5680                                    names, strchr(names, ',') ? "s" : "");
5681                         kfree(names);
5682                 } else
5683                         btrfs_warn(fs_info,
5684                                    "can't clear %s bits 0x%llx while mounted",
5685                                    type, disallowed);
5686                 return -EPERM;
5687         }
5688
5689         return 0;
5690 }
5691
5692 #define check_feature(fs_info, change_mask, flags, mask_base)   \
5693 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,       \
5694                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
5695                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
5696                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5697
5698 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5699 {
5700         struct inode *inode = file_inode(file);
5701         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5702         struct btrfs_root *root = BTRFS_I(inode)->root;
5703         struct btrfs_super_block *super_block = fs_info->super_copy;
5704         struct btrfs_ioctl_feature_flags flags[2];
5705         struct btrfs_trans_handle *trans;
5706         u64 newflags;
5707         int ret;
5708
5709         if (!capable(CAP_SYS_ADMIN))
5710                 return -EPERM;
5711
5712         if (copy_from_user(flags, arg, sizeof(flags)))
5713                 return -EFAULT;
5714
5715         /* Nothing to do */
5716         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5717             !flags[0].incompat_flags)
5718                 return 0;
5719
5720         ret = check_feature(fs_info, flags[0].compat_flags,
5721                             flags[1].compat_flags, COMPAT);
5722         if (ret)
5723                 return ret;
5724
5725         ret = check_feature(fs_info, flags[0].compat_ro_flags,
5726                             flags[1].compat_ro_flags, COMPAT_RO);
5727         if (ret)
5728                 return ret;
5729
5730         ret = check_feature(fs_info, flags[0].incompat_flags,
5731                             flags[1].incompat_flags, INCOMPAT);
5732         if (ret)
5733                 return ret;
5734
5735         ret = mnt_want_write_file(file);
5736         if (ret)
5737                 return ret;
5738
5739         trans = btrfs_start_transaction(root, 0);
5740         if (IS_ERR(trans)) {
5741                 ret = PTR_ERR(trans);
5742                 goto out_drop_write;
5743         }
5744
5745         spin_lock(&fs_info->super_lock);
5746         newflags = btrfs_super_compat_flags(super_block);
5747         newflags |= flags[0].compat_flags & flags[1].compat_flags;
5748         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5749         btrfs_set_super_compat_flags(super_block, newflags);
5750
5751         newflags = btrfs_super_compat_ro_flags(super_block);
5752         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5753         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5754         btrfs_set_super_compat_ro_flags(super_block, newflags);
5755
5756         newflags = btrfs_super_incompat_flags(super_block);
5757         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5758         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5759         btrfs_set_super_incompat_flags(super_block, newflags);
5760         spin_unlock(&fs_info->super_lock);
5761
5762         ret = btrfs_commit_transaction(trans);
5763 out_drop_write:
5764         mnt_drop_write_file(file);
5765
5766         return ret;
5767 }
5768
5769 static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
5770 {
5771         struct btrfs_ioctl_send_args *arg;
5772         int ret;
5773
5774         if (compat) {
5775 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5776                 struct btrfs_ioctl_send_args_32 args32;
5777
5778                 ret = copy_from_user(&args32, argp, sizeof(args32));
5779                 if (ret)
5780                         return -EFAULT;
5781                 arg = kzalloc(sizeof(*arg), GFP_KERNEL);
5782                 if (!arg)
5783                         return -ENOMEM;
5784                 arg->send_fd = args32.send_fd;
5785                 arg->clone_sources_count = args32.clone_sources_count;
5786                 arg->clone_sources = compat_ptr(args32.clone_sources);
5787                 arg->parent_root = args32.parent_root;
5788                 arg->flags = args32.flags;
5789                 memcpy(arg->reserved, args32.reserved,
5790                        sizeof(args32.reserved));
5791 #else
5792                 return -ENOTTY;
5793 #endif
5794         } else {
5795                 arg = memdup_user(argp, sizeof(*arg));
5796                 if (IS_ERR(arg))
5797                         return PTR_ERR(arg);
5798         }
5799         ret = btrfs_ioctl_send(file, arg);
5800         kfree(arg);
5801         return ret;
5802 }
5803
5804 long btrfs_ioctl(struct file *file, unsigned int
5805                 cmd, unsigned long arg)
5806 {
5807         struct inode *inode = file_inode(file);
5808         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5809         struct btrfs_root *root = BTRFS_I(inode)->root;
5810         void __user *argp = (void __user *)arg;
5811
5812         switch (cmd) {
5813         case FS_IOC_GETFLAGS:
5814                 return btrfs_ioctl_getflags(file, argp);
5815         case FS_IOC_SETFLAGS:
5816                 return btrfs_ioctl_setflags(file, argp);
5817         case FS_IOC_GETVERSION:
5818                 return btrfs_ioctl_getversion(file, argp);
5819         case FITRIM:
5820                 return btrfs_ioctl_fitrim(file, argp);
5821         case BTRFS_IOC_SNAP_CREATE:
5822                 return btrfs_ioctl_snap_create(file, argp, 0);
5823         case BTRFS_IOC_SNAP_CREATE_V2:
5824                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
5825         case BTRFS_IOC_SUBVOL_CREATE:
5826                 return btrfs_ioctl_snap_create(file, argp, 1);
5827         case BTRFS_IOC_SUBVOL_CREATE_V2:
5828                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
5829         case BTRFS_IOC_SNAP_DESTROY:
5830                 return btrfs_ioctl_snap_destroy(file, argp);
5831         case BTRFS_IOC_SUBVOL_GETFLAGS:
5832                 return btrfs_ioctl_subvol_getflags(file, argp);
5833         case BTRFS_IOC_SUBVOL_SETFLAGS:
5834                 return btrfs_ioctl_subvol_setflags(file, argp);
5835         case BTRFS_IOC_DEFAULT_SUBVOL:
5836                 return btrfs_ioctl_default_subvol(file, argp);
5837         case BTRFS_IOC_DEFRAG:
5838                 return btrfs_ioctl_defrag(file, NULL);
5839         case BTRFS_IOC_DEFRAG_RANGE:
5840                 return btrfs_ioctl_defrag(file, argp);
5841         case BTRFS_IOC_RESIZE:
5842                 return btrfs_ioctl_resize(file, argp);
5843         case BTRFS_IOC_ADD_DEV:
5844                 return btrfs_ioctl_add_dev(fs_info, argp);
5845         case BTRFS_IOC_RM_DEV:
5846                 return btrfs_ioctl_rm_dev(file, argp);
5847         case BTRFS_IOC_RM_DEV_V2:
5848                 return btrfs_ioctl_rm_dev_v2(file, argp);
5849         case BTRFS_IOC_FS_INFO:
5850                 return btrfs_ioctl_fs_info(fs_info, argp);
5851         case BTRFS_IOC_DEV_INFO:
5852                 return btrfs_ioctl_dev_info(fs_info, argp);
5853         case BTRFS_IOC_BALANCE:
5854                 return btrfs_ioctl_balance(file, NULL);
5855         case BTRFS_IOC_TREE_SEARCH:
5856                 return btrfs_ioctl_tree_search(file, argp);
5857         case BTRFS_IOC_TREE_SEARCH_V2:
5858                 return btrfs_ioctl_tree_search_v2(file, argp);
5859         case BTRFS_IOC_INO_LOOKUP:
5860                 return btrfs_ioctl_ino_lookup(file, argp);
5861         case BTRFS_IOC_INO_PATHS:
5862                 return btrfs_ioctl_ino_to_path(root, argp);
5863         case BTRFS_IOC_LOGICAL_INO:
5864                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
5865         case BTRFS_IOC_LOGICAL_INO_V2:
5866                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
5867         case BTRFS_IOC_SPACE_INFO:
5868                 return btrfs_ioctl_space_info(fs_info, argp);
5869         case BTRFS_IOC_SYNC: {
5870                 int ret;
5871
5872                 ret = btrfs_start_delalloc_roots(fs_info, -1);
5873                 if (ret)
5874                         return ret;
5875                 ret = btrfs_sync_fs(inode->i_sb, 1);
5876                 /*
5877                  * The transaction thread may want to do more work,
5878                  * namely it pokes the cleaner kthread that will start
5879                  * processing uncleaned subvols.
5880                  */
5881                 wake_up_process(fs_info->transaction_kthread);
5882                 return ret;
5883         }
5884         case BTRFS_IOC_START_SYNC:
5885                 return btrfs_ioctl_start_sync(root, argp);
5886         case BTRFS_IOC_WAIT_SYNC:
5887                 return btrfs_ioctl_wait_sync(fs_info, argp);
5888         case BTRFS_IOC_SCRUB:
5889                 return btrfs_ioctl_scrub(file, argp);
5890         case BTRFS_IOC_SCRUB_CANCEL:
5891                 return btrfs_ioctl_scrub_cancel(fs_info);
5892         case BTRFS_IOC_SCRUB_PROGRESS:
5893                 return btrfs_ioctl_scrub_progress(fs_info, argp);
5894         case BTRFS_IOC_BALANCE_V2:
5895                 return btrfs_ioctl_balance(file, argp);
5896         case BTRFS_IOC_BALANCE_CTL:
5897                 return btrfs_ioctl_balance_ctl(fs_info, arg);
5898         case BTRFS_IOC_BALANCE_PROGRESS:
5899                 return btrfs_ioctl_balance_progress(fs_info, argp);
5900         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5901                 return btrfs_ioctl_set_received_subvol(file, argp);
5902 #ifdef CONFIG_64BIT
5903         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5904                 return btrfs_ioctl_set_received_subvol_32(file, argp);
5905 #endif
5906         case BTRFS_IOC_SEND:
5907                 return _btrfs_ioctl_send(file, argp, false);
5908 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5909         case BTRFS_IOC_SEND_32:
5910                 return _btrfs_ioctl_send(file, argp, true);
5911 #endif
5912         case BTRFS_IOC_GET_DEV_STATS:
5913                 return btrfs_ioctl_get_dev_stats(fs_info, argp);
5914         case BTRFS_IOC_QUOTA_CTL:
5915                 return btrfs_ioctl_quota_ctl(file, argp);
5916         case BTRFS_IOC_QGROUP_ASSIGN:
5917                 return btrfs_ioctl_qgroup_assign(file, argp);
5918         case BTRFS_IOC_QGROUP_CREATE:
5919                 return btrfs_ioctl_qgroup_create(file, argp);
5920         case BTRFS_IOC_QGROUP_LIMIT:
5921                 return btrfs_ioctl_qgroup_limit(file, argp);
5922         case BTRFS_IOC_QUOTA_RESCAN:
5923                 return btrfs_ioctl_quota_rescan(file, argp);
5924         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5925                 return btrfs_ioctl_quota_rescan_status(file, argp);
5926         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5927                 return btrfs_ioctl_quota_rescan_wait(file, argp);
5928         case BTRFS_IOC_DEV_REPLACE:
5929                 return btrfs_ioctl_dev_replace(fs_info, argp);
5930         case BTRFS_IOC_GET_FSLABEL:
5931                 return btrfs_ioctl_get_fslabel(file, argp);
5932         case BTRFS_IOC_SET_FSLABEL:
5933                 return btrfs_ioctl_set_fslabel(file, argp);
5934         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5935                 return btrfs_ioctl_get_supported_features(argp);
5936         case BTRFS_IOC_GET_FEATURES:
5937                 return btrfs_ioctl_get_features(file, argp);
5938         case BTRFS_IOC_SET_FEATURES:
5939                 return btrfs_ioctl_set_features(file, argp);
5940         case FS_IOC_FSGETXATTR:
5941                 return btrfs_ioctl_fsgetxattr(file, argp);
5942         case FS_IOC_FSSETXATTR:
5943                 return btrfs_ioctl_fssetxattr(file, argp);
5944         case BTRFS_IOC_GET_SUBVOL_INFO:
5945                 return btrfs_ioctl_get_subvol_info(file, argp);
5946         case BTRFS_IOC_GET_SUBVOL_ROOTREF:
5947                 return btrfs_ioctl_get_subvol_rootref(file, argp);
5948         case BTRFS_IOC_INO_LOOKUP_USER:
5949                 return btrfs_ioctl_ino_lookup_user(file, argp);
5950         }
5951
5952         return -ENOTTY;
5953 }
5954
5955 #ifdef CONFIG_COMPAT
5956 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5957 {
5958         /*
5959          * These all access 32-bit values anyway so no further
5960          * handling is necessary.
5961          */
5962         switch (cmd) {
5963         case FS_IOC32_GETFLAGS:
5964                 cmd = FS_IOC_GETFLAGS;
5965                 break;
5966         case FS_IOC32_SETFLAGS:
5967                 cmd = FS_IOC_SETFLAGS;
5968                 break;
5969         case FS_IOC32_GETVERSION:
5970                 cmd = FS_IOC_GETVERSION;
5971                 break;
5972         }
5973
5974         return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
5975 }
5976 #endif